You can use marginnote
.
\begin{example}
\marginnote{\includegraphics[width=0.5\marginparwidth]{example-image-a}} ........
Code:
\documentclass[12pt,twoside,openright,a4paper,oldfontcommands]{memoir}
\usepackage{mdframed}
\usepackage[table]{xcolor}
\definecolor{exampleBorder}{RGB}{235,235,235}
\newenvironment{example}{%
\mdfsetup{frametitlealignment=\raggedright}
\begin{mdframed}[
outerlinewidth=0,
skipbelow=5pt,
skipabove=5pt,
innertopmargin=8pt,
innerbottommargin=8pt,
innerleftmargin=8pt,
innerrightmargin=8pt,
linecolor=exampleBorder]%
}{%
\end{mdframed}%
}
\usepackage{marginnote,graphicx}
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{example}
\marginnote{\includegraphics[width=0.5\marginparwidth]{example-image-a}}
This is an example. This is an example. This is an example. This is an example.
This is an example.
\end{example}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\clearpage
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{example}
\marginnote{\includegraphics[width=0.5\marginparwidth]{example-image-b}}
This is an example. This is an example. This is an example. This is an example.
This is an example.
\end{example}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\end{document}

If you are using memoir
, then you can use either sidepar
or marginpar
provided by memoir
without any need for additional packages. But remember that \marginpar
floats and \sidepar
doesn't.
\documentclass[12pt,twoside,openright,a4paper,oldfontcommands]{memoir}
\usepackage{mdframed}
\usepackage[table]{xcolor}
\definecolor{exampleBorder}{RGB}{235,235,235}
\newenvironment{example}{%
\mdfsetup{frametitlealignment=\raggedright}
\begin{mdframed}[
outerlinewidth=0,
skipbelow=5pt,
skipabove=5pt,
innertopmargin=8pt,
innerbottommargin=8pt,
innerleftmargin=8pt,
innerrightmargin=8pt,
linecolor=exampleBorder]%
}{%
\end{mdframed}%
}
\usepackage{graphicx}
\setmarginnotes{5mm}{25mm}{0.5\baselineskip} %% <---- adjust these.
\sideparmargin{outer}
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{example}
This is an example. This is an example. This is an example. This is an example.
\sidepar{\includegraphics[width=0.5\marginparwidth]{example-image-a}}
This is an example.
\end{example}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\clearpage
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{example}
This is an example. This is an example. This is an example. This is an example.
\sidepar{\includegraphics[width=0.5\marginparwidth]{example-image-b}}
This is an example.
\end{example}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\end{document}

This is another approach using tikz
. Here you can get rid of mdframed
and do everything with tikz
but as I don't know your use cases, I left mdframed
untouched. This works with any document class.
\documentclass[12pt,twoside,openright,a4paper,oldfontcommands,table
]{memoir}
\usepackage{mdframed,tikz}
\definecolor{exampleBorder}{RGB}{235,235,235}
\mdfdefinestyle{exampl}{
outerlinewidth=0,
skipbelow=5pt,
skipabove=5pt,
innertopmargin=8pt,
innerbottommargin=8pt,
innerleftmargin=8pt,
innerrightmargin=8pt,
linecolor=exampleBorder,
}
\mdfsetup{frametitlealignment=\raggedright}
\surroundwithmdframed[style=exampl]{Example}
\usepackage{environ}
\usepackage{ifoddpage}
\newcommand{\Graphics}[1]{\includegraphics[width=0.5\marginparwidth]{#1}}
\NewEnviron{Example}[1][]{%
\ignorespacesafterend
\checkoddpage
\ifoddpage
\noindent
\begin{tikzpicture}
\node[inner sep=0pt,outer sep=0pt,text width=\linewidth,align=justify] (a) {\BODY};
\node[anchor=west,inner sep=0pt,outer sep=0pt,overlay] at ([xshift=2em]a.east)
{#1};
\end{tikzpicture}%
\else
\noindent
\begin{tikzpicture}%
\node[inner sep=0pt,outer sep=0pt,text width=\linewidth,align=justify] (a) {\BODY};
\node[anchor=east,inner sep=0pt,outer sep=0pt,overlay] at ([xshift=-2em]a.west)
{#1};
\end{tikzpicture}%
\fi
}%
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{Example}[\Graphics{example-image-a}]
This is an example. This is an example. This is an example. This is an example.
This is an example.
\end{Example}%
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{Example}
This is an example. This is an example. This is an example. This is an example.
This is an example.
\end{Example}%
\clearpage
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\begin{Example}[\Graphics{example-image-b}]
This is an example. This is an example. This is an example. This is an example.
This is an example.
This is an example. This is an example. This is an example. This is an example.
This is an example.
This is an example. This is an example. This is an example. This is an example.
This is an example.
This is an example. This is an example. This is an example. This is an example.
This is an example.
This is an example. This is an example. This is an example. This is an example.
This is an example.
This is an example. This is an example. This is an example. This is an example.
This is an example.
This is an example. This is an example. This is an example. This is an example.
This is an example.
\end{Example}
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam gravida dolor vestibulum,
semper eros nec, accumsan quam. Fusce in auctor erat, eget interdum magna. Duis semper odio
\end{document}
