The One With The Metaphorical Tunnel - S3-E4
Revealing mistake: While Chandler and Janice are in D'Agostino's, some grocery products have their names partially covered, such as Uncle Ben's and Grape Nuts.
Starring: Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matthew Perry, David Schwimmer, Matt LeBlanc
The One With The Metaphorical Tunnel - S3-E4
Revealing mistake: While Chandler and Janice are in D'Agostino's, some grocery products have their names partially covered, such as Uncle Ben's and Grape Nuts.

The One With The Birth Mother - S10-E9
Visible crew/equipment: When Joey's telling Phoebe about having been at a nice restaurant with his date and how she took fries off his plate, in the shots facing Joey in the restaurant we can see the end of the set wall, with a 2x4 framed plywood board and a heavy duty extension cord hanging there.
The One With Chandler In A Box - S4-E8
Monica: Fine, judge all you want to, but [to Ross] married a lesbian, [to Rachel] left a man at the altar, [to Phoebe] fell in love with a gay ice dancer, [to Joey] threw a girl's wooden leg in a fire, [to Chandler] LIVING IN A BOX!
The One With The Prom Video - S2-E14
Trivia: The first day Courteney Cox donned the 'Fat Monica' make-up and costume, Matthew Perry walked right past her without recognizing who she was.
The One With the Sharks - S9-E4
Question: What's the name of the "scary painting" that Joey saw in the apartment of the girl he thought he'd slept with before? The strange and creepy painting (black and white, with an amorphous body and a chair). I really, really want to know who is the artist. Not Gladys - that's Phoebe's painting that comes out of the frame.
Answer: The painting doesn't have a name, and if it does it is never mentioned in this episode.
Suggested correction: I've seen a few of these listed as errors, but they're not. A lot of shows do this often if you pay attention. It's called "product displacement", and it is done to avoid being sued or having to pay licensing fees. Also, it is cheaper to alter logos like this than pixelate/blur them out. What is interesting though, is that one of the grape nut boxes in this picture does not have an altered logo.
Yes, it's product displacement, and this is specifically referred to as the "greeking" process. However, your correction only offers an excuse as to why this occurs. The tape or paint partially or fully covering the brand names or logos are a distraction, and it removes viewers from the fake reality of the show or movie. Originally, these types of submissions were to be listed in trivia, but instead they were placed in the mistake section.
Super Grover ★