Is it a reference to a previous game or is it recycling already finished work? Whatever it might be, it's impossible to deny that, with the exception of a few vehicle placements, less fog and a little more light, the pictures above could almost be a spot the difference. Things have been changed a little bit to make it more appropriate for the competitive shooter crowd, but the two pictures above could undoubtedly have been taken in the same location.
After quite a bit of controversy last year over Modern Warfare 3's use of recycled content, it'll be interesting to see reaction to this come Counter-Stike: Global Offensive's launch (if it gets any mention, that it). Reaction to this screenshot, though, has been defensive; some are claiming that the similarities are coincidental, others say "that's how buildings look," and sometimes it's just being met with a flat out denial that the setting looks anything like Left4Dead.
It's only based on this single map so far, which, to be fair, is enough to say that it's a nice reference and little else. No doubt curious gamers will be on the lookout for other references as they play.
Source: Reddit
