Trivia: The three casting directors at the end of this episode are really Kevin Bright, Marta Kauffman, and David Crane, the creators/executive producers of Friends.
Trivia: In the dance class, when the real Monica meets the fake Monica, Monica says to her she's Dutch. When they're about to dance Fake Monica asks Monica: "Mag ik deze dans van u?", which is Dutch for, "May I have this dance?"
Goof: When Monica and Fake Monica are telling Rachel about sneaking into a hotel in one shot Monica separates the bread and starts to spread the mayo on it, it then cuts to Fake Monica, and back to Monica and she separates the bread and spreads mayo on it again.
Trivia: In the scene where Ross has just explained to Joey and Chandler that he has to give up Marcel, there is a commercial break. Immediately after the break, the shot shows the three guys sitting on the sofa in the coffee house. If you look at the positions that their hands are in, they are mimicking the "See no evil, Hear no evil, Speak no evil" monkeys.
Continuity: In "The One Where the Monkey Gets Away", Ross tells Rachel that keeping Marcel is illegal and if the officials find out, then he will be taken away. However, in this episode Ross takes Marcel to the vet's without a moment's thought. Surely if the monkey was being kept illegally, he wouldn't take him to a vet's office where that fact would be made public.
Goof: Joey says that the peeper was watching him walk around his apartment in his underwear, but his apartment is on the other side of the building from Monica and Rachel. The peeper would not be able to see into his apartment. Furthermore, Joey says he can't cook naked because of the peeper, but their kitchen is nowhere near the window.
Continuity: The back closet, later called the "secret closet", is open during the scene where Joey calls Sydney. In it you can see what looks like coats hanging up, but in "The One with the Secret Closet", Chandler claims to have never seen what's in there, and when he does, it's nothing but clutter. Additionally, in that episode the door opens from the right, outwards, but in this episode, it opens inward from the left.
Goof: When Monica is organizing the search for Marcel, she says to Chandler and Joey, "You guys take the first and second floor, Phoebe and I will take third and fourth". In the very next shot, Monica and Phoebe are knocking on Heckles' door, #8, on the first, or at most, second floor.
Continuity: The light switch that Ross uses to turn out the lights when he's alone with Rachel was added for this episode. It's not there in the previous episode, "The One with All the Poker". Furthermore, in "The One with the Fake Monica", two episodes later, the switch has been moved to the right. It is now closer to the picture frame and the toggle switch has been replaced with a rotating dimmer switch.
Goof: You can clearly see that it's not Heckles who picks up Marcel.
Goof: How did Marcel get outside onto the balcony? He went out the front door and Rachel, who was in the apartment the whole time, would have seen him come back.
Note: Monkeys are expert at climbing, so he had in all likelihood climbed up the fire escape on the outside of the building. In a later scene, we see him coming through a window into a hallway, which is probably how he got out to the fire escape in the first place.
Goof: When Monica is reading the engagement notices, she turned the page. In the next shot, the page isn't turned.
Continuity: For this episode, a larger circular table top has been placed on top of Monica's kitchen table, likely to accommodate the fact that with six players at the table, all the cards, poker chips, food and drinks, the existing table was just too small. The larger top is of a darker wood, but you can see the existing smaller table top in honey-colored wood beneath it. The added top is on the table throughout the entire episode, but is not there in the preceding or following episodes.
Trivia: In the first poker game when Chandler is making his joke about settling the Jamestown colony of Virginia, they use the same reaction shot of Rachel twice. She folds her arms and gives Chandler a "look"; just before and again just after he says, "You see, King George is giving us the land, so...".
Goof: When Rachel raised the bet after she found out that she wasn't hired, the reflection of the moving camera and camera operator are visible on the window behind Monica.
Trivia: When Rachel impressively shuffles the cards she is using a trick deck.
Continuity: Rachel seems surprised by her lack of typing ability, however, in "The One with Mrs. Bing", it was only too obvious when the gang was reading her manuscript.
Goof: When Marcel is dancing, you can clearly see the reflection of someone directing him by moving their hand up and down.
Trivia: Marcel was not actually dancing in this episode. The clip was just looped.
Factual Error: When playing Scrabble, Ross tells Phoebe that he doesn't think "scrunchy" is a word. It actually is; defined as "an elastic band covered with gathered fabric, used to fasten the hair, as in a ponytail". It can also be spelled "scrunchie".