Elegant and modest. I have wondered why Trier issued a "loins draped" version of Genius, when Genius was naked elsewhere.
Many of the earlier GENIO types depicted the Genius with his loins draped. This is particularly the case with the GENIO POP ROM series from London. Plus, it was probably colder in Trier.
The switch from the free-balling Genius of old to the modest one was a western thing that happened at the British and Gallic mints under control of Constantius I. Older depictions of Genius Pop. Rom. have him with with draped loins such as on this Hadrian aureus, but Diocletian's monetary reform had with himation (or whatever that piece of clothing is) draped over his shoulder instead, at all mints, and I don't think that ever changed in the east. The permanent switch from towel-over-shoulder to wrapped around waist first happened at Trier under Constantius I as augustus. Here's the before and after versions. The draped loins version had very rarely been used earlier under Constantius at both London and Lyons, but very much as an exception. For example, here's one on a British Museum London coin from 297 AD (under Constantius I as caesar). Once the change had happened at Trier it was permanent, but the other western mints (London, Lyons) only followed a year or so later under Constantine I (vs is father). Constantine's first GPR issue at each of London & Lyons have the old immodest Genius, then the second and subsequent ones have him covered up. It's certainly interesting why this change took place. Nowadays we might think of it as an issue of modesty, but I doubt Constantius did. Perhaps it was a return to a more traditional depiction (per Hadrians aureus, above) vs Diocletian's chosen one?