I added some software to the site that allows for larger pictures to be used - it automatically resizes the pictures and the file. Seems to work pretty well, but if the original photo is really large, the compression may still be larger than the 200kB limit. It will either tell you that or it may show an error.
btw, it automatically downsizes the pictures to 1024 wide x 800 high (or whichever is greater), so that fit on the screen better.
The picture of my car was originally 3393x1973 and was 633kB.