
Considering it doesn't show from the front, it could just be light artifact from case edge, the step on the back of the matrix or the backplane (reflective piece behind matrix). The sellers doesn't seem to put much effort into their sales, so it is doubtful they would have toyed with the insides like that, to make a tiny sale.
The characters look correct, I have the exact same model I'm using for comparison. Part of the problem is they took a photo at a closeness few would ever view their watch at. At that distnce you might be catching a reflection of the edge of their photo tent. WHo knows?