The lesbian, Countess Geschwitz, dances tango with Lulu, in ‘Pandora’s Box’ 1929

Ray Batchelor writes: What should we make of this 1929 queer tango from Weimar Germany? https://youtu.be/ecd0OV4E1YA The clip shows Lulu dancing with Countess Augusta Geschwitz (Louise Brooks and Alice Roberts) and is probably the earliest film showing a lesbian dancing tango with another woman. Was it a tango they danced?