Who is Itadori talking about? What flashback
So starting from the top right, that's Yuta speaking I think, and he's probably talking about Maki who has a short hair cut. (Manga)
Then there's Megumi on the left, the text is actually what he said to Todo when Todo asked Megumi about his type of woman.
On the bottom, Yuji's confused about who is who becuase Yuta & Megumi's head icons look similar. Yuji's also refering to the Todo moment when he's talking about the flashback.
Nobara is roasting Megumi's basic, boring ass answer to Todo's question.
And finally Megumi is in the middle of talking about when he got asked the question by Todo before being cut off by Nobara.
(Edit: Why did I spend time answering this)