[Robert DeLong]

The ears on the left picture stick out further than the ears on the right picture, with out question.

The face is more squared on the left than it is on the right.

Could be he lost weight, making it look different Ditto with the smile also. Slightly different angles also, might make facial features appear different as well.

Can't really say definitively that the pictures are or aren't of the same person.

[Round Earther]

At his height, he is taller than >99.5% of males in the United States. That might make it a bit difficult to find a body double.

[octex]

Even the texture of his beard is different.