Studios Leavesden on Supergirl, with Craig Gillespie at the ... the Communist Superman ‘Red Son’ or the costume from The CW’s ‘Supergirl’ with the blue background and a very thin ...

though we've since confirmed that it's fan-made and not an official first look at Supergirl: Woman of Tomorrow's logo and theme (the latter is actually pulled from The CW's Supergirl TV series).