Other mistake: Twelve seconds into the intro, the shot of the store with the name Adrian Grenier above it is mirrored. Notice the reversed lettering in the signs. (00:00:10)
Suggested correction: Does something in the intro count as a mistake? Even still, the signs could be facing the inside of the store on purpose, making it look like a reverse image from the outside. Just to the right of the store with Adrian Grenier's name on it, we see a sign for Pizza displayed correctly.
I would say, for this type of intro, it should be considered a mistake. I'd call it an "other mistake" as it wasn't done deliberately. There's no way the reversed imaged signs point into the store. The photo store has a solid sign that's not inward facing, with the word "Kodak" flipped. The neon signs facing outwards are also flipped. And the pizza signs are also incorrect. The p and z's are flipped as well.
You're absolutely correct, I do see the reverse print on the photo store. Oddly enough, one of the pizza signs is displayed correctly, however.
Other mistake: In the opening scene, Ari calls Eric at 5:42 a.m. There is way too much sunlight coming through both of their windows for it to be that hour.