As root, execute this command:
cp /usr/share/icons/Rodent/48x48/apps/xsane.png /usr/share/pixmaps
Then with mousepad, create a file called xsane.desktop and copy these contents to the file:
[Desktop Entry]
Encoding=UTF-8
Name=XSane
Comment=Scanner Access Now Easy
Exec=xsane
Icon=xsane
Terminal=false
Type=Application
Categories=Application;Office;
Then, as root, move this xsane.desktop file to /usr/share/applications.
An icon will show up under Office.
You've asked about creating launchers a couple of days ago, and lots of possible solutions were provided.
This one is just copy/paste, so I hope you'll try it.
(another way to help is to test packages that show up in the testing repository. Sometimes they slip by without icons, so the earlier the packagers catch that, the earlier they fix it)