Which JXL supports, by the way. Tiling is mandatory for images bigger than 2048x2048, and you can construct images based on an 8x downscaled version, recursing that up to 4 times for up to 4096x downscaling.
By the "g as in graphics" logic for "gif", for "jpeg" we have "j as in joint", "p as in photographic", "e as in experts", and "g as in group", so "je-feck"?