Burnside
Freakalicious
Correct. That's called perspective.Here is version 4 on the left compared to the picture of Cooper. The angle of the chin doesn't look exact to me (if you refer to the lines I highlighted),
Reference shot is a head looking up, while the model looks straight at ya.
Apart from the chin angle you could pin point that ears should be located higher and the guy should have a turn-up nose. All this is based on this reference alone.
How about now?