.....I thought it was an obvious joke.
The Photoshop mistakes are plentiful. Plus, human muscle doesn't develop in the shapes you see there, steroids or not. His lack of chest mass compared to his lats is next to possible, biceps and shoulders aren't that separated when a body builder gets that big, quads are almost never bigger then upper body, etc. Much smaller (probably natural) guy that was Photoshopped in a funny/bigger way.
The real give away: Body builders today don't get that big without the help of growth hormone. Problem with that is it increases the size of EVERYthing, including internal organs. This means the intestines enlarge as well as the muscles, and push against the abdominal wall, which makes it basically impossible to have that nice "V" shape anymore (like back in Arnolds days). Their stomachs actually look bloated when they're not flexing, today. It'* really an odd/freaky sight to see someone with shredded abs and obloquies, but yet, their stomachs sticking out past their chest.