Foreshortening can be a tricky thing to get right. One minute your image is bursting out of the frame, the next you seem to have assembled a cast of deformed mutants. The strange thing is that the picture above is in order, from right to left: OK; a bit dodgy; a lot dodgy; freakish.
Here’s a close-up of the last one. The shadow doesn’t really help either.
Thanks to Will!