Consider following MWE :
\documentclass{report}
\usepackage{tabularx}
\usepackage{graphicx}
\begin{document}
\begin{tabular}{|c|c|}
\hline a & b \\ \hline
\rotatebox[origin=c]{90}{Hello} & d \\ \hline
e & f \\ \hline
\end{tabular}
\vspace{1cm}
\begin{tabular}{|c|c|}
\hline a & b \\ \hline
\rotatebox[origin=c]{90}{There} & \includegraphics[height=2cm]{dummy.png} \\ \hline
e & f \\ \hline
\end{tabular}
\end{document}
In the second line of the first table, the rotated text ("Hello") is vertically aligned with the text ("d") of its adjacent cell.
In the second table, there is a problem with the vertical alignment : the text seems to be aligned at the bottom [or left before rotation], and there is a whitespace below the figure. How can one obtain vertical alignment in this case?
I found this related question but it seems my problem is caused by the fact of adding an image in the adjacent cell.
There
(as you used origin=c) and along the bottom of the image, so space has to be added under the image to allow both to sit on the baseline.\llap{\rule{1in}{0.5pt}}
AFTER the text.