It seems to me to be a word that image description generators (and potentially image generators, too) "believe" to exist. If that's correct that was likely caused by parsing chunks of actual words, such as "arabesque", "Arabic", "coffee", "giraffe", as if ara+ffe were two actual morphemes (units of meaning).
For reference, this site claims that [I think?]diffusion models think that a similar word, "arafed", exists; and that's basically going slow, taking one's time, leisurely.
I mentioned in another comment chain, but: even if we claim that "araffe" is ultimately from Welsh "araf", we're still left with the double consonant and the ending -e to explain - those don't even appear in the conjugation of "arafu".