By now the infamous black robe Hux wears in Phasma is its own character, and we all have a precise image in mind. Needless to say, that’s a sexy, silky and half-naked image. But. There is a but. Indulge me for a second.
In SW not only are robes common articles of outdoor clothing, but they are also charged with meaning: they are what Jedi and Sith wear. A black robe is a Sith robe. Emperor Palpatine used to wear a simple black robe. Robes are uniforms. And Hux wears his robe like a uniform.
I like the idea of Armitage getting ready for Kylo, in his wanton, silky and sexy robe, as much as any other girl does; but I am becoming more and more convinced that, in his downtime, General Hux dresses up like the old Emperor. Besides, we know from Before the Awakening that Hux is one of the hugest nerds the Galaxy has ever seen: he takes the time to explain how Starkiller works to the stormtroopers – even to those working in sanitation! Him cosplaying Palpatine is just the next little (oh, so little!) step.
[OR. Or. If Hux’s robe is actually intentionally reminiscent of a Sith robe, there might be some plottier implications. But that is a topic for another post]