In act II Iago makes assumptions about women and moors and also he uses these assumptions in his evil plan to break Othello

During the conversation with Emilia and Desdemona Iago talks about his interpretation of women’s behavior

Come on, come on; you are pictures out of doors,

Bells in your parlors, wild-cats in your kitchens,

Saints in your injuries, devils being offended,

Players in your housewifery, and housewives’ in your beds

In his eyes women are being pretty when outside, being messy and noisy at home and causes nothing but trouble.

You rise to play and go to bed to work.

in his speech Iago thinks that women’s major role are on the bed

When Iago is talking to Othello that his marriage won’t last and he said reason and his assumption about Othello:

Mark me with what violence she first loved the Moor, but for bragging and telling her fantastical lies:

he thinks Othello wins Desdemona’s love thru fantastical lies and he thinks that Othello the Moor is good at lying

Her eyes must be fed; and what delight shall she have to look on the devil?

loveliness in favor, sympathy in years, manner and beauties; all which the Moor is defective in:

Iago’s speech shows in his mind a Moor is lack of  loveliness, manner and beauties and a woman like Desdemona will going to seek another man.