After being rejected so bluntly, Vera had doubted conclusions for a second her.
However, while washing the dishes, she realised that it wouldn't be fun if it was too easy. In no way would Neven accept a woman throwing herself at him like that. Especially if he wanted to play.
There was a part of her that was turned on by the situation, and being rejected so plainly hurt her pride.
What was the point of getting that amulet if not to make her do all sorts of things? How dare he refuse her offer after securing that she wouldn't flee from his clutches ever again?
Not just that he wanted her to be willing - which was an easy feat, actually - but also to prove it! And he wanted her to prove it better than just asking for it!
The poor dishes felt her mood while she rubbed the sponge on them. When she was done, they shined more than when they had just been bought.
However, all that rumbling and cleaning allowed her to come up with a thousand ideas.