When Darrin shrinks a few inches at the office, his shirt sleeves and pant legs are way too long for him. When he's shrunk 3-4 ft and arrives home, his pants fit him fine, his suit jacket is now only slightly baggy.
Samantha tells her mother it's the first time Endora has referred to her husband by his actual name, Darrin, but this already happened in The Joker Is a Card (1965).
During the final scene, whilst Darrin is still small, his height changes depending on the camera angle. As the camera is looking at him from in front, he is barely taller than the mayonnaise jar lying next to him, yet when the camera goes to the side, he is clearly taller, as the mayonnaise jar is only beside his legs.
The closet in the entry way has always been on the stair wall. In this episode the closet is on the opposite wall.
At the end when the small Darrin is standing on the coffee table, his suit is a solid olive green. But when Endora brings him back to regular size, his suit is a medium blue pinstripe.
It is said that it is Darrin and Samantha's fifth anniversary, but they married in 1964-only four years earlier.
Update: The time in the show is different than the time in real life.
Update: The time in the show is different than the time in real life.
The Kravitz's live across the street. But, the camera shows them walking down the Stephens' driveway and showing a park behind them. Since episode two, Mrs. Kravitz has spied out their front window, across the street at the Stephens home.
Normal size chair and high chair were the right size for tiny Darrin to sit in. In human dimensions, no child, nor doll could have used them. Lost in Space (1965) viewers - used to gigantic dial phones - had seen the proportional mistake.
Frank O'Hara (Irish-American alcoholic drunk) grabs Darrin's mayonnaise jar that viewers today would buy at Costco, but not in 1968 America. It had held between one to two quarts of mayonnaise.
Frank O'Hara could not see the pony in the driveway. Standing outside at the corner of the den (at the doorway) the pony stood in front of the garage that is adjacent to where the kitchen/back side of the den would be.