Continuity mistake: When Aunt Bethany asks "Do you hear it?", she leans forward in her chair. In the next shot she's suddenly sitting back, and leans forward again when she says, "It's a funny squeaky sound."
Continuity mistake: When Clark's neighbours return home, the man says to Clark, "Where do you think you're going to put a tree that big?" The trunk is very large, bigger then Clark's feet. Clark replies, "Bend over and I'll show you." Then Clark cuts the tree trunk - it is very thin and easy for him to cut.
Continuity mistake: When Clark is stapling the lights to the roof, his leg is tangled in the sting of lights causing him to lose his balance and slide of the roof. As he slides/falls grabbing the gutter the string of lights around his leg disappears.
Continuity mistake: After Clark dedicates the Griswold Family Christmas tree and it expands, Ellen's hands are on her hips, but the next quick shot of her shows her hands clasped behind her back.
Continuity mistake: When Rocky runs out of the RV and stands in front of his mom, her mittened right hand is on his shoulder but in the next shot it's not.
Continuity mistake: After Clark cuts the rope restraining the tree branches, Rusty is very close to the tree, but the final shot when Clark gives the "OK" sign shows Rusty about two feet from the branches.
Continuity mistake: After Eddie's arrival Clark is on the lawn with "Snots." Clark's left had is shown as he is there alone with the dog trying to get his attention and his glove and wedding ring have both disappeared.
Continuity mistake: When the grandfather is sleeping in the top of the bunk bed, there's a cheesecake poster on the ceiling. When Clark falls through the attic floor onto the bunk bed, it's not there.
Continuity mistake: In the scene of Clark standing in the snow trying to figure out why his Christmas lights did not work, the paper he is holding in his right hand is mid torso to him, but in the next shot when Rusty leaves him, his right hand has instantly dropped to his side and he raises his paper-holding hand again.
Continuity mistake: When Clark, Eddie, and Catherine are admiring the Christmas lights of the Griswold house, Clark is very close to Eddie with his left arm draped over Eddie's shoulder, but the next quick cut to Clark when he says, "Eddie?", shows Clark further away and his left arm at his side, and not stretched out.
Continuity mistake: In the Christmas dinner scene, closeups of Rocky show his right hand raised to his face, but the overhead shots do not.
Continuity mistake: The first time Clark fails with the lights, Ellen's mother says she hopes the kids see what a waste of resources it is. During this scene the level of her martini changes.
Continuity mistake: After the tree burns, Rusty says, "Dad's gonna flip out." Clark Sr.'s left elbow is close to and behind Rusty's head, but in the next instant shot of Rusty, Ellen, and Audrey, Clark Sr.'s elbow is not there.
Continuity mistake: When Santa Clause's sled passes in front of the moon at the end, why is the sea so dark? It wasn't in previous shots.
Continuity mistake: When Clark is looking at his "bonus check", he's holding both the envelope and "check" together in both hands. In the next shot he's only holding the "check" in both hands and the envelope is no longer under it.
Continuity mistake: When Clark falls over while on the ladder, after ripping his sleeve off, his hands keep changing position on the ladder. When he first starts to fall, his right hand is gripping the side and in the next shot both hands are gripping the rung. In the next shot both hands are on the side of the ladder until the shot after he pushes himself away from the tree and they go back to being on the rung for a shot.
Continuity mistake: When Clark has the entire family outside to witness the lighting of the house, the positions of the in-laws change instantly from being clumped together to strung out in a line, depending on whether the shot is overhead or at ground level.
Continuity mistake: The entire Christmas bonus scene at end, Clark's tie changes. Take note of the pattern on the knot, which changes from shot to shot.
Continuity mistake: When Clark is talking to the pretty saleswoman and she says "well, you do have your coat on", he tilts his head down and to his right. In the next shot his head is to his left and he moves it to the right.
Answer: They are desk organizers.
I'm wondering maybe it was one of the gags in the movie where the boss got the same gift from all the employees. I know there's a lot of gags in the vacation movies.
movielove