The Girls jumping all over Samantha's pot belly.
Yes, it seemed rather sudden & out of character for vain Samantha to have the belly, but they acted like she emerged with the tattoo of a penis on her forehead!
Not to mention Charlotte herself was quite pudgy at least once (its most noticeable in the episode where they all go to Staten Island & Charlotte gets very drunk and dances in public).
I'd say this cloud is Cumulo Nimbus.
Didn't he discover America?
Penfold, shush.