Honestly, he's just really fluffy on the left. He probably has a very similar muscle build underneath all that fat. Maybe gained a couple extra pounds of muscle when losing it, but the build is definitely similar.
The guy on the left ~isn't that bad~. That being said, all men, without exception, should be in if not peak shape, at least close to it. That this has been so neglected that guy on left is better than most is pathetic.
However, the guy on the right is in the middle of a workout. He doesn't look like that all the time.