How to place a figure/image next to TOC element

Question

I am searching to put a figure/image next to a TOC chapter element.

At the moment I only found a way to put it just under it but not either before the number of the chapter or after the page. \addstufftotoc{\nobreak\protect\includegraphics[height=1\baselineskip]{Image/en.jpg}\par}

Answer 1

Here I use the feature of specifying a separate heading in the toc to add the graphic, via lap, if necessary.

\documentclass{article}
\usepackage{graphicx}
\begin{document}
\tableofcontents
\noindent\hrulefill
\section{Normal section}
\section[{\llap{\includegraphics[height=\baselineskip]{example-image}%
  \kern20pt}Left of section number}]{Left of section number}
\section[{Right of title \includegraphics[height=\baselineskip]{example-image}}]%
  {Right of title}
\section[{Right of page  number\hfill\rlap{\kern20pt\includegraphics%
  [height=\baselineskip]{example-image}}}]{Right of page  number}
\end{document}

---

SUPPLEMENT

In response to comments about the use of \chapter in the book class, and vertical alignment of the image, I provide an additional MWE:

\documentclass[a4paper,openright]{book}
\usepackage{graphicx}
\DeclareRobustCommand\addimg[1]{\llap{\raisebox{-\dp\strutbox}%
  {\includegraphics[height=\baselineskip]{#1} \kern20pt}}}
\begin{document}
\tableofcontents
\noindent\hrulefill
\chapter[\addimg{example-image}Left of section number]{Left of section number}
\chapter[\addimg{example-image}Machines d'audit et processus MCO et MCS]{Machines d'audit et processus MCO et MCS}
\end{document}

Answer 2

I'm coming back here because I didn't notice that the image is showing up on the header where it's used :

I would like to remove the image or put it on the side, if it's possible.