The Paro Tsechu Mask dance show (Large Head Mask), is during the JUDGEMENT DAY mask dance show, which means that after we die, the God and the God of death would justify our deeds...and if we have done good deeds, we will be taken to heaven and if more bad deeds, then to hell.
The large red mask with skulls around the top is the God of Death(Yamantaka).
Thanks Phorba!