I know the You Tube move as "Drop Sit"; but, different schools - different names.
I don't know the name of the move in the pic. 'Cos it is easy to lead with an experienced dance partner I have always just done it rather than call it first. I would be happy for this one to be "Russian Kicks". It has a kind of Cossack aspect.
(At the risk of getting off topic I must add that a while back, in a discussion group for teachers that my Association convened, we talked about letting new dancers know that some moves have multiple names. Getting the teachers to agree to a set of standardised names was out of the question. :mrgreen
several years ago I was talking to Frankie about your first example, and he said that members of WLH (himself included) had created it after watching a similar ballet movement, and called it the "Russian splits." That step, whichsubsequently tended to follow the "back Charleston" became known later as the "kick between the legs" and even later I think as the "kick Charleston" (although I'm not too certain about the last one). Thus as is the way with dance you seem to have come across a pretty close derivation of the original name!