Empress Maria knitting
Is she actually knitting? It looks to me as if she's doing some tapestry or heavy embroidery - even carpet work.
The portraits on the wall are very interesting - I recognise the Winterhalter portrait of her daughter Maria, her son Nicholas, her father-in-law Nicholas I, and a very large photo which looks to be one of the family (where they all look rather uncomfortable). I'm not sure about the central portrait though - is that Alexander II? His hair looks wrong somehow - though this could be the effect of some sort of military headgear. Anyway, a fascinating photograph!