The wager is on. Barney shakes hands with Lily here and agrees to wear Marshall's ducky tie if he loses.
Added:
The gang is suited up here and ready to go. It's a classic promotional shot of the HIMYM cast.
Added:

How I Met Your Mother Season 7 Episode 3 Quotes

Robin: Lily what on Earth is going on with your cans?
Lily: Oh these old thangs? I got my pregnancy boobs!

Duck duck gross!

Barney