Monroville said:

I always figured that Vader was on his kneeling holo circle that he was on when speaking to the Emperor (ie Veers is projected in much the same way when speaking to Vader). Thinking about that, it looks like Vader is on one knee, as you can only see his left foot, which can only be bent at the knee due to how short the distance between his foot and his hip is:

I highly doubt that Vader is kneeling because Vader in Ady's refilmed shot is standing up yet matches the proportions of the old shot. Also, why would Vader ever kneel before Veers?