This is Juno signing “please,” which she does reflexively whenever she says the word aloud (as does her older brother):
Remember: she’s only two-and-a-bit. “Please” isn’t something that she says every time, despite our constant, (mostly) gentle prodding. But I know that she’s internalized the expectation, as evidenced by this conversation had last night at dinner:
Juno: I want some apple juice.
Me: (saying nothing, just making eye contact)
Juno: Say please.