Excellent work. I’m just blown away with the leather hat. The face is beautifully rendered, shadow values could be a touch deeper with a stronger sense of light and shadow direction to build dimensional form. The fabrics are well textured and convey a sense of the weave and pile. The green background is nicely our of focus, could have been muted a little to throw the subject forward.
When it comes to appraising a portrait I agree the technical attributes are important. I also look for some essence of humanity, some sense of context and narrative and above all an insight into the personality of the subject. I want to read, hear, smell, feel and see the artists conception of the person.
Freud did this in spades, his work is powerful because these qualities are front and centre in his portraiture.