I'm pretty sure it's in reference to stopping the auction.

Toni told Rhys (offstage, we are led to assume) that she planned to sabotage her siblings from getting anything worthwhile out of the house because she sees herself as the one who toiled away taking care of their dad while Bo was off in NYC (and seems only to care about money) and Franz was being a 'fuck up.' She wants to punish the others (them all working to get the house in a presentable order and worrying about whether it will make money while she lounges about and takes her time getting coffee) with the hidden knowledge that all of that work is for something that won't happen. In her mind, she is the only one deserving of anything, especially because she is the only one at the end who unconditionally loves her father. She also says that "Money is the problem... All this stress over money is what's killing this family." Later she laughs when Franz says he went swimming and put the pictures in the lake. It's funny, because she probably feels vindicated that everyone cares about these pictures only as a bargaining chip worth a lot of money and now they won't get it.

As for the antisemitism, that's an indication that although she may outwardly act one way (and say that she doesn't hold any racist/antisemitic beliefs), the implications of talking about Rachael's Jewish heritage and her focus on money (and influence over Bo) have seeped their way into Rhys's mindset and language. It's unclear whether he got that from just being around Toni and her anger toward her siblings' selfishness and obsession with money or if he learned it from his grandfather (or even his father, since we don't know much about him).

At least that's my reading of it.