Going up in an abrupt manner: The elf is frightened or startled and wants to hear as best as they can as quick as they can.
Going up in a more smooth manner: The elf is happy or pleased in some way and wants to draw attention to themselves to bask in said pleasure
One ear goes up and the other ear goes down in an abrupt matter: The elf heard something that they want to hone in on from the side of the raised ear. The lowered ear lowers noise from the other direction while the raised ear heightens it from the direction in question.
One ear goes up and the other ear goes down in a smooth manner: The elf is confused and wishes to appear off balance so as to indicate such. (This might be a learned gesture meant to accent the tilting of the head)
Going down in an smooth manner: The elf sad or upset and wishes to appear smaller
Going back: The elf is angry or annoyed. This limits hearing slightly and indicates the elf is “closed off” to whatever upset them.
Ears going crazy: Sometimes happens when an elf is feeling hella embarrassed around the person the love. Like a human stammering for words.
Ears going forward: Cannot actually happen.