Hi Nina,
Yes, I would suggest gluing the picture to the bottom of the bezel. Otherwise, you may trap a bubble that can come up some time during the curing process but not escape the resin, leaving an annoying bubble in your otherwise perfect pendant.
If the picture is laminated with a good sealed edge, you do not need to seal it before including in the resin. You can see what I mean by a sealed edge in this video on the Resin Obsession you tube channel: http://www.youtube.com/watch?v=86R7QBst4_o