Vertical alignment of figure in multirow-cell inside tabu table

Question

We have a tabu table with figures and \multirow cell which contails a long figure (XeLaTeX is used). Minimal working example is in the end.

The Figure (arrow) is attached after the actual result.

Alignment rules

• column heading is centered (vertically and horizontally), colored and bold;
• 1,2,4 columns are centered vertically and left edge horizontally;
• 3,5 columns - centered both vertically and horizontally.

set by

\taburulecolor{DarkBlue}
\tabulinesep = 2mm
\begin{tabu} to 170 mm {
        |X[2,m]
        |X[1.5,m]
        |X[0.6, C,m]
        |X[2,m]
        |X[0.6, C,m]|
        }


\rowfont{\centering\bfseries\color{Blue}}

Column 5 has a Figure in multirow cell \multirow{8}{*}{\includegraphics[height=8cm]{arrow.PNG}}. It does not align to vertical center. Why? How to do it?

Arrow

MWE

\documentclass[10pt, oneside, a4paper]{report}
\usepackage[left=2cm,right=1.5cm,
    top=2cm,bottom=2cm,bindingoffset=0cm]{geometry}
\usepackage{indentfirst} 
\usepackage{titlesec}
\usepackage{tabu}
\usepackage[svgnames]{xcolor}
\definecolor{DarkBlue}{HTML}{0070C0} 
\definecolor{Blue}{HTML}{1C8CCC} 
\usepackage{multirow}
\usepackage{polyglossia}
\setmainfont[Ligatures=TeX]{Arial}


%--------------------------------------------
\begin{document}

\taburulecolor{DarkBlue}
\tabulinesep = 2mm
\begin{tabu} to 170 mm {
        |X[2,m]
        |X[1.5,m]
        |X[0.6, C,m]
        |X[2,m]
        |X[0.6, C,m]|
        }


\rowfont{\centering\bfseries\color{Blue}}

\hline

Status
    & Visual indication
    & Symbol
    & Audible signal
    & Priority\\ \hline

Alarm active, not acknowledge 
    & Red, blinking 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Accompanied by an audible signal, as 3 short audible signals repeated every 7 s
    & High 
    \\ \hline

Alarm active, silenced 
    & Red, blinking 
    & picture % \includegraphics[width=0.5cm]{symbol.png} 
    & Silent 
    & \multirow{8}{*}{\includegraphics[height=8cm]{arrow.PNG}} 
    \\    \tabucline{1-4}

Warnings active, not acknowledged
    & Yellowish orange, blinking 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Accompanied by an audible signal, as 2 short audible signals, to be repeated at least once per 5 min or be replaced by an alarm 
    & \\ \tabucline{1-4}

Warnings active, silenced 
    & Yellowish orange, blinking 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent 
    &   \\ \tabucline{1-4}

Rectified --- unacknowledged alarm
    & Visual indication 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent 
    & \\ \tabucline{1-4}

Rectified --- unacknowledged warning
    & Visual indication 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent 
    & \\ \tabucline{1-4}

Alarm active, acknowledged 
    & Visual indication 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Suppression of audible signal (silent)
    & \\ \tabucline{1-4}

Warnings active, acknowledged
    & Visual indication 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent 
    &  \\ \hline

Caution active 
    & Yellow 
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent 
    & Low \\ \hline

Normal state 
    & Empty field 
    & None
    & Silent 
    &  \\ \hline

\end{tabu}
\end{document}

Answer 1

• added package [export]{adjustbox} for determine image baseline in its vertical center
• corrected number of lines, which are spanned by multirow, to 13 (you need to count all lines in spanned rows)
• use option = for \multirow, which preserve column formatting in its cell
• added missing graphicx package (option demo is only for test purposes, since i haven't your image)

\documentclass[10pt, oneside, a4paper]{report}
\usepackage[left=2cm,right=1.5cm,
    top=2cm,bottom=2cm,bindingoffset=0cm]{geometry}
%\usepackage{indentfirst}
%\usepackage{titlesec}
\usepackage{tabu}
\usepackage[svgnames]{xcolor}
\definecolor{DarkBlue}{HTML}{0070C0}
\definecolor{Blue}{HTML}{1C8CCC}
\usepackage{multirow}
%\usepackage{polyglossia}
%\setmainfont[Ligatures=TeX]{Arial}
\usepackage[demo]{graphicx}
\usepackage[export]{adjustbox}


%--------------------------------------------
\begin{document}

\taburulecolor{DarkBlue}
\tabulinesep = 2mm
\begin{tabu} to 170 mm {
        |X[2,m]
        |X[1.5,m]
        |X[0.6, C,m]
        |X[2,m]
        |X[0.6, C,m]|
        }
\rowfont{\centering\bfseries\color{Blue}}
    \hline
Status
    & Visual indication
    & Symbol
    & Audible signal
    & Priority\\ \hline

Alarm active, not acknowledge
    & Red, blinking
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Accompanied by an audible signal, as 3 short audible signals repeated every 7 s
    & High
    \\ \hline

Alarm active, silenced
    & Red, blinking
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent
    & \multirow{13}{=}{\includegraphics[height=8cm,             % <--- span 13 lines of text
                                       width=\linewidth,        % <---
                                       valign=m]{arrow.PNG}}    % <---
    \\    \tabucline{1-4}

Warnings active, not acknowledged
    & Yellowish orange, blinking
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Accompanied by an audible signal, as 2 short audible signals, to be repeated at least once per 5 min or be replaced by an alarm
    & \\ \tabucline{1-4}

Warnings active, silenced
    & Yellowish orange, blinking
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent
    &   \\ \tabucline{1-4}

Rectified --- unacknowledged alarm
    & Visual indication
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent
    & \\ \tabucline{1-4}

Rectified --- unacknowledged warning
    & Visual indication
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent
    & \\ \tabucline{1-4}

Alarm active, acknowledged
    & Visual indication
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Suppression of audible signal (silent)
    & \\ \tabucline{1-4}

Warnings active, acknowledged
    & Visual indication
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent
    &  \\ \hline

Caution active
    & Yellow
    & picture % \includegraphics[width=0.5cm]{symbol.png}
    & Silent
    & Low \\ \hline

Normal state
    & Empty field
    & None
    & Silent
    &  \\ \hline

\end{tabu}
\end{document}