When Mr Ross (Warren Frost) is at Monks, after Elaine (Julia Louis-Dreyfus) leaves you can see that he has his hands behind his back one second, before the next shot shows him with his hands in his pockets.
When Elaine is talking to the waitress at the coffee shop, the waitress is holding a menu in one hand. After Darryl sits down it cuts back to the waitress and she is now holding a glass of orange juice and a menu.
Elaine's (Julia Louis-Dreyfus) purse moves from her shoulder to not being visible at all when she is talking to Jerry (Jerry Seinfeld) & George (Jason Alexander) about the possibility of Darryl (Samuel Bliss Cooper) being black.
A pocket organizer can't fax or do email.
When Kramer is greeting people on his campaign trail, it's obvious there is a doll, not a real baby in the baby carriage pushed by the mom.