Screwed.

You just purchased a pair of screws from a Puzzlanian hardware store. In your mind's eye, you imagine the two screws interwoven as shown above, and each being rotated in the direction the arrows show. The top-left screw is rotated counter-clockwise as viewed from the direction of its head, the bottom-right screw is rotated clockwise as viewed from the direction of its head.

First, you notice that something is unusual about the two screws. Secondly, you wonder how the screws should be moving in your mind's eye. If they were rotated according to the arrows, will they become closer, move farther apart, or stay at the same distance.

In solving this puzzle, it may or may not be necessary to discover what is unusual about the screws.