Now Cobb and Ariadne are in some market place talking. There's something odd about this market, though…
Ah. Of course. It's a dream market. When Ariadne realizes it's a dream everything explodes and then she wakes up.
When they go back under (i.e. fall asleep again) Ariadne walks around creating things and Cobb is quite impressed. However, he warns her to not change too many things or his populated subconscious (cough, cough* Mal cough*) will attack her (which happens sometimes).
He also tells her never to replicate a real location (which seems to be a piece of advice that is very personal to him).