What little plot there is serves no purpose. The new character created specifically for the spin-off (or perhaps borrowed from another property?) amounts to a joke(?) about the online art scene and that's about it.
Bringing Jolyne back for the purpose of sex appeal is probably unavoidable given that the Part 6 anime is currently airing and waifu culture is at an all time high in the west and in Japan, but they could have at least tried to do something interesting with it.
