Continuity mistake: During brunch outside, Miranda's bite on her muffin changes shape between the side and the front shot.
Continuity mistake: During the girls' chit-chat, the amount of ice tea in Miranda's glass suddenly decreases between shots.
Continuity mistake: While eating outside with Miranda and her baby, Carrie takes a french fry to her mouth, but her hand suddenly disappears in the following shot.
Answer: A popular brand of sexual lubricant. See http://www.k-y.com/index.jsp.
J I Cohen