Pots are made to be held and used. You should be able to feel the weight in your hands and the texture of the glaze or the clay body against your skin. Does the handle fit the hand well? If there’s no handle does the cup sit in the hands comfortably? A photo shows you a little but hides a lot and I’ve always thought people had tremendous faith to buy a pot from an unknown potter (me) based on a photograph.
Since I’ve opened a pottery shop with a coffee bar I see people use my pots everyday which in itself is very rewarding. If I sell I mug it’s great but I never see that mug again or see the person enjoy it. Serving coffee in my own cups and seeing people enjoy them never gets old.