My first beer is done!

So I pop my first beer today and it came out good. It taste like a belgian ale should. http://i.imgur.com/n5ACFkO.jpg

http://i.imgur.com/QTn60dQ.jpg

My only issue is its a tad on the flat side. would this have anything to do when it was brewing the stopper blew off because i did not have enough room in the carboy? Or am I missing a step in the process after adding the priming sugar during bottling?