Who wouldn't want to wear a fishbowl helmet in space? Neither of them need it, but it is fun to wear them and it looks cool. The helmets and headsets also make it possible to talk to each other.

The picture goes along with this story: https://www.deviantart.com/kittyelfie/art/Titan-Attacks-Comet-Girl-903956430

I don't know how https://www.deviantart.com/stmercy2020 managed to get this photograph.