Heres a couple of images of a bird not long out of the nest, @ 28 days old.
puffing itself up to appear as large as possible & closing eyes
I dont know if its more comical than it is intimidating!
means business - rocking & swaying with more bill-clacking, fluffed right out & beginning to show flight feathers.
Flight feathers on show - it was time for us to go...
We saw the male, keeping watch from the sidelines :-
A similar scenario at another location on an evening visit :-
During that time i was wondering why i wasnt hearing any begging calls from the juvs - she was obviously aware of me & shut them up..... i took this image of her doing her best to avoid detection & headed off.