Is it permissible for a man to look at pictures of his deceased wife in which a part of her awrah appears or her head is uncovered?

A man is permitted to look at a picture of his deceased wife without her hijab, because the marital relationship does not end with death. He is also allowed to wash her and look at her.

However, if looking at her picture without a hijab leads to lust, or evokes memories of the marital relationship, or intensifies grief and sorrow, then it should be avoided.