What a vivid visceral madness this is!
Is this how Gertrude perceived Hamlet in the previous scene? Did she see turmoil in him like this? A frothy roiling fight?
Or is this an exaggeration for Claudius’ benefit?
Hamlet has told her to tell Claudius he is mad – which would imply that he thinks she thinks he is not so. But there is nothing in his behavior in that scene that would indicate non-madness from her perspective.
Here’s what she saw:
• her son suddenly whipping out his blade and run it through a curtain into Polonius
• her son seeing someone who wasn’t there – a ghost, he says, the ghost of his father. She sees no indication of a ghost.
• Her son ranting and raving, being inappropriately personal about her sex life and talking non-stop in a kind of mania.
I don’t think she’s lying when she says he’s mad. It’s just a matter of degree. Is he sea storm mad or pebble in a lake mad?