Emma acted out the scene first, and then Helena Bonham Carter mimicked what she did. so it was Helena Bonham Carter pretending to be Emma Watson pretending to be Helena Bonham Carter pretending to be Bellatrix pretending to be Hermione pretending to be Bellatrix.
Considering what $8 million turned “Blackwater” into, it’s interesting to see what similar sums have done at other studios. In its last season, Friends paid its six leads $1 million per episode, so that’s $6 million right there. The total costs for the final season were $7 million per episode, meaning that for roughly the same price as an all-out Westerosi brawl you could get the gang hanging out and gabbing at Central Perk.