She simply became oblivious when these subjects were started.
'Why should a horse want to put itself in the human power ?' asked Ursula.

'That is quite incomprehensible to me.

I don't believe it ever wanted it.' 'Yes it did.

It's the last, perhaps highest, love-impulse: resign your will to the higher being,' said Birkin.
'What curious notions you have of love,' jeered Ursula.
'And woman is the same as horses: two wills act in opposition inside her.

With one will, she wants to subject herself utterly.