Ok, guys. As you know, this is Marth:
And, this is Marth's face:
Let's see if it fits Chrom:
I guess not, right? But, if we make the eyes smaller, so the face looks bigger, and change the position of the mouth and the nose, we can get this:
And here's Chrom. It's basically a matter of smoothness (and maybe blurriness). Oh, the left eye is a little off, but enough with edits. It's 00:50 here and I'm going to work early.
My veredict: It's fake. Unless the guy managed to take the picture from the same height and angle as Marth's picture. If you don't see it, open the last two images on different tabs and compare them.
Good night.