When the male customer looking for a Valentine's card for his wife cheaper than $1 first approaches Jonah and Amy, he walks up directly behind them. When the camera angle changes, he is suddenly standing about 6 feet away.
When Glenn is recording the wedding video for Rose, in the camcorder POV shot, a woman with gray hair wanders into the shot behind him. When it cuts to a regular shot, the woman has suddenly disappeared.
When Dina's birds are escaping, none of them casts a shadow.
Glenn says he spends 16-19 hours a day at Cloud 9. His subsequent explanation does not add up. He says he gets to the store at 4 AM, then stays all day and 2 hours past closing time to prepare his comments for the next day's morning meeting. It has been established that the store closes at 11 PM. If he stays 2 hours after that, he'd be there until 1 AM, meaning he'd be there 21 hours a day, not 16-19.