I first thought the name must be a clever pun when I saw that the original JPEG was dated 1992. But sadly my brain was off by a decade, JPEG XL is in fact not J

I first thought the name must be a clever pun when I saw that the original JPEG was dated 1992. But sadly my brain was off by a decade, JPEG XL is in fact not JPEG 40. They could have gone with JPEG XXL or JPEG XXX but the former is a bit too fanciful and the latter might cause some adoption problems outside a certain niche industry.