During the barbeque Gina argues with Eddie. At the end of the argument she asks him to give her a sausage link which he put on her plate. When she gets to the door she takes a bite out of a hot dog.
In the first Barbershop, the tattoo of the woman is on Ricky's left arm. In the sequel, it appears on his right arm. This may not be evident because he is wearing mostly long-sleeved shirts in the first movie, but one of the deleted scenes shows him in a tank-top and the tattoo is visible.
When the first ever sign went up announcing the rival "Nappy Cutz" franchise, Calvin and the others run across the street to look at the sign. A long shot of them reveals a brand new coffee shop behind them. Later in the film, we see the coffee shop in the process of just being built.
When Calvin is eating breakfast and talking to Miss Emma, he lifts his empty fork. In the next shot, his fork is full of eggs, though he never made any movement to pick them up.
In one scene, Isaac pulls up the "Nappy Cutz" website on his Mac laptop to show the rest of the barbershop. However, the active application seen in the insert shots is plainly seen to be "DVD Player", not a web browser, revealing that the video clips that are supposed to be from the website are being run from a DVD disc or local file.
When Alderman Brown and the TV crew enter Calvin's barbershop, the red 'tally' light on the front of the camera is flashing, so is the warning light on the rear left. Flashing red indicates either a low battery, slack tape or internal humidity. It can also mean 'running up to speed' but any cameraman worth his weight would already be turning over BEFORE he enters the shop, not during.
A flashback to 1969 shows Eddie meeting Loretta on Chicago's Red Line train. The Red Line did not begin operating until 1994.
The CTA "L" cars used in the flashback to 1969 were not in service back then. They started using the 2600 series cars in the early-'80s
In the flashback where Eddie was running from the police in the alley on the 4th July there were speed humps in the alley. Chicago didn't put speed humps in alleys until 2000.
In the theatrical version, a film camera and cameraman are clearly visible in a mirror when all of the reporters are in the barbershop. (it was edited out for the DVD release.)
When Queen comes out of the back of the styling shop to go after Cedric the crew and cameras are reflected in the door she comes out of.