As a response to 10 was holding it in so he could see all his companions again as himself and could do no longer when he reached the TARDIS. The build up of energy made it explode out of him whereas with 9 he just let it happen.
Ohila (Sister of Karn): ‘You have a little under four minutes to live.// Doctor: ‘Four minutes? That’s ages. What if I get bored? I need a television, couple of books, anyone for chess… bring me knitting. (from 'The Night of the Doctor' minisode) ♥♥
He's beauty. He's grace. He'll punch racists in the face. The Twelfth Doctor, ladies and gentlemen was gonna pin this cuz I just knew that that was gonna happen in the episode, but now I'm pinning it for that comment XD