It is public record about Wanda's and Pietro's background. We had a full rehash of their bios a few episodes ago when Agent Haywood was going through Wanda's background. It is not hard for anyone to know where Pietro's from. Whomever is portraying Pietro should know the general basics of his background and where he and Wanda are from and their general powers. Again, when he was speaking on childhood memory, he was more than likely making it up and using Wanda's emotional state as an excuse that she's suppressing her memories which gives him cover.
But trying to assume that every Easter Egg means more than just an Easter Egg, don't overthink it. Keep in mind, this is still WANDA'S WORLD. The only difference from this episode from the rest is that she's losing control. So, there are "pop references" like of Kick-Ass which stars both the Quicksilver actors. And that could be summed up that she seen the movie before and recognized that fake Pietro's face from that movie. It is clear that in the MCU they have pop references, so it's not unheard of, plus you see while they were leaving the theater the show titles of "The Incredibles" and "The Parent Trap", both meta-references that speaks on Wanda's current mindstate and her world. It's not much more deeper than that.
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