I also noticed the picture is a .png file, is that the only picture file type that this feature works on? Doesn't seem to work on other sites.

first thing that happened when I opened IE - crashes

IE Tab is like turning Firefox into a woman. It gives you the stagnant, squishy hole in the middle, but without all the useless, bloated bits around it.

The reason it shows up as a "different" image in IE is because IE's rendering engine fails to comply to a host of standards and even fully implement rendering of a lot of things, such as png transparency or, as is showcased with this image, png gamma settings. All png images can have a chunk, or tag if you will, that specifies what gamma setting it should be rendered with. Firefox, Opera, Chrome, Safari etc all obey this gamma chunk and so display the "right" image. IE doesn't and will instead render the image far brighter than it should. The pixels that appear to be black in most browsers aren't entirely black and when their gamma is cranked up you can see the other image easily as the "right" one now consists of near-white pixels instead.

after i got FF on this computer, haaven't had any viruses/worms whatsoever

when i got this computer it came with ,connected to internet and loaded clusters/troijans in no time

so FF FTW