I can see the gap I think she is talking about. Start numbering the prongs from the top upper left. See how on prong #4 (the last whole prong that you can see on the right) on the underside of the diamond; the underside doesn't lay against the prong like it does on #2.
Or maybe it's just an illusion, I don't know...I'm certainly no expert!
Or maybe it's just an illusion, I don't know...I'm certainly no expert!