Remove spiderweb.jpg or replace with smaller image

I'm not sure what the purpose of css/spiderweb.jpg is, since grepping for that filename through the module didn't return any results (so it's apparently not being used?), but it takes up 400+KB which is like 2/3 of the module's size, so it'd be great if it was either removed (if it really is not being used), or just replaced with a compressed version.