cedega ebuild (5.0.1) installs its icons in /usr/share/icons/48x48/transgaming.png /usr/share/icons/32x32/transgaming.png /usr/share/icons/Cedega.xpm /usr/share/icons/16x16/transgaming.png this icons should be in /usr/share/icons/hicolor, and xpm icon should be in /usr/share/pixmaps...
file a bug upstream