While it appears as though there was never a question of Abendroth's authority, notice that here he makes a show of performing his power for the Nazis as well as the other girls. He leaves no room to question his power, as he's even able to make Lara complicit in what he did to Zoya. In a more overarching way, Abendroth's actions demonstrate the utter cruelty and depravity of which humanity is capable.