First off you are laying down and extending your gut while you press.
You are pushing the muscles out.
The distention doesn't appear to be any issue at all. Stand up and exhale and squeeze your abs? Are they still distended or actually appear more normal?
Next as most have said, correct your diet and work on the bf%. You will see huge differences and then so can we, and that will allow members to evaluate what's really going on there more appropriately. Good luck and happy lifting