Alliteration and word play, bum as in a person who devotes a great deal of time to a specified activity,
and bum highlighted by her fluffy tail as in a person's buttocks in British slang.
I wanted the rabbit to look more like a bunny than a human as you can see from the prompt.
However, this ambiguity may be more interesing.
Is she the fashionista tennis novice equivalent of a ski bunny with her character now showing on the outside?
Or is she a natural born bunny in a cartoon world like Bugs Bunny that is more human-like than bun-bun-like and devotes a great deal of time to tennis?
Or ... word play and imagery run amok ...
This is a workup image from Artistly.ai that looked better than all of the 17 attempts in NightCafe after import of the text prompt with prompt magic.