After looking at it yesterday and today again, I have concluded that it is
not him. I do not have the expertise that others here have, but from my lay perspective, the nose and ear comparisons indicate that it isn't him.
I looked at 2 photographs of him in later life for comparison of his ear placement on his head. Specifically, I was looking for where the top of his ear aligned with his eyebrows. I used the photograph on the right to find the angle of his head where the top of his ear would align with his eyebrow. Notice that the bottom of his nose doe not show the nostrils. This indicates a different nose angle or different nose bridge length.
When comparing a more straight on look such that the nostrils are showing, the top of his left ear is not aligned with his eyebrow.
Though it bears a little similarity upon first glance, I'll put myself out there and say that it isn't him.
My analysis isn't anywhere close to as good as bmarlowe's and I'm certain that my description falls short, but it was enough to convince me that the kid isn't Cobb.