The Steam games window supports icons to be added in front of your mod. These icons are .TGA (Targa) files consisting of:
- 16x16 pixel and a separate 32x32 pixel image
- 32-Bit or 24-Bit colors
- No RLE Compression
It can be placed anywhere in your mod's directory, but you will also need to add this parameter to the gameinfo.txt file to tell Steam where it is omitting the .TGA extension:
To have the 32x32 image be displayed next to the mod name when the game is selected, it must have the same name and path as the 16x16 image with _big at the end of the file name before the file extension.