Continuity mistake: During breakfast, when Carrie says she "worked harder than her SATs" Sam's mug is close to Charlotte's bowl, but a shot later Sam is holding her mug, This swaps back and forth.
Continuity mistake: During breakfast, when Sam says "Honey, he's a keeper", lighting screens are reflected on her sunglasses.
Continuity mistake: When Miranda talks about her date licking her butt, the food on her fork disappears between shots.
Continuity mistake: At the store, Tricia's daughter is looking at the left or straight on, depending on the angle.
Visible crew/equipment: When Charlotte shows Tray the refurbished bedroom, a squared set light is reflected on the wardrobe.
Continuity mistake: When the girls are drinking Martini, Miranda lowers her glass twice.
Continuity mistake: When Carrie confesses Charlotte that she is calling Aidan, the dancers moving and waving their arms wildly behind Charlotte disappear between shots. One might argue that it's because of the angle of the shot, but they're all moving around all the time and at least their arms should be visible.
Continuity mistake: During dance class, when Carrie confesses she calls Aidan, the same woman walks behind her twice.
Continuity mistake: During dance class, when the teacher says "every movement has a meaning" Carrie's right arm is down or raised depending on the shot.
Ghost town - S4-E5
Continuity mistake: The bite on the cake changes all the time between shots.
Ghost town - S4-E5
Continuity mistake: When Sam says she'll go to the inauguration, the invitation lies between both tables but a shot later it is just on one table.
Ghost town - S4-E5
Continuity mistake: During diner, when Miranda talks about the ghost and says "I've been living there...", her hands are holding the glass or not, and extended or not depending on each shot. No continuity in any.
What's sex got to do with it? - S4-E4
Continuity mistake: When Charlotte is showering, a bunch of foam on her forehead appears and disappears and reappears again randomly depending on the shot.
Continuity mistake: The musician leaves a note for Carrie on top of the napkin. A shot later the napkin is inches away and the note is on top of the glass table.
Continuity mistake: When Charlotte asks if Big and Carrie are friends, her fork is pointing upwards or downwards depending on the shot. Also, the pinched omelette appears and disappears randomly.
Continuity mistake: During breakfast, when Carrie says she spent the night with Big, the pancake on Miranda's fork appears and disappears randomly.
The real me - S4-E2
Continuity mistake: When Oscar tells Carrie that her hair is all wrong, he moves his left arm up and down and signals her, but from the front angle his arm is lowered and doesn't move an inch.
Continuity mistake: When Charlotte asks if Tray is her boyfriend or lover, Miranda's fork is lying on the plate or held in his hand, depending on the angle.
The real me - S4-E2
Continuity mistake: When Oscar tells Carrie about looking like a whale, his assistant is either by his side or behind him. This changes back and forth.
The real me - S4-E2
Continuity mistake: When Oscar shakes the underwear at Carrie, the position of his thumb holding the clothes hanger changes between shots.
Answer: Yes, it is.