At one point she starts mouthing off at Jay and Jay defends himself 'cause Bey looks at him while he's talking. Solange then starts pointing at Jay and even says something to Julius (he's just doing his job
). Things calm down, but she starts pointing at everybody again and Bey looks at her and says something I think (looks like she's shaking her head or maybe she's just looking down). Bey stands in front of Jay when Solange gets closer, like she's afraid she's gonna hit him again. I think she was talking about something that happened very recently. Maybe Jay did something at the party that really upset her or maybe he said something out of line. Then Bey says something to Jay right before they walk out, like she's telling him what to do.
When she first confronts him in the elevator she gets in his face and starts using her hands and Jay-Z knocks them out of his face, that sets her off and she goes a bit balistic. I get that. She's angry and he touched her, doesn't matter if he's just defending himself. When you're angry you don't want anyone touching you.
I don't think Solange meant to fight him, I think she was just gonna cuss him out, but it escalated.
This looks like some kinda Maury ratchet episode 
she's still acting all perfect in there 