umm... quite difficult to answer such a question.... a lot depends on what you mean by 'plain ordinary cat pictures'......maybe the IR gurus here can chip in. :think:
All I can say is that in IR photography, the colours of objects that we see and take for granted under normal light appear differently. The colours (of the fur and eyes, etc) of the cats in these photos don't look like they do in normal light (check them out in the album in my signature if you are interested).
Another way of looking at this is that these pics could also be interesting to see (to those who are interested in the first place, of course

) because it is downright difficult if not impossible for non-IR modified cameras to capture such IR shots in the shade especially of subjects like cats which don't like to stay still while you shoot even if you were using a normal camera.