The second dress doesn't seem like it would be flattering on anyone. Even the model doesn't look good in it. The first dress is pretty and the blue is a fun color for a wedding.
Number two looks like it would make both my stomach and butt look bigger while still exposing my saddlebags (My stomach isn't usually a problem area. I do have a round butt though). I don't know who it would flatter. But if it looks good on you, then go for it!