I think they look short next to your tall headboard.

..square

Either one, I think. I would probably do round in the bed room and square in the living room. I've been meaning to buy some like these. Nice choice. Also, i can't imagine them being any taller with out looking ridiculous.

You didn't ask but is there another wall where you can place the bed, away from the window? Then you would have a solid wall behind each lamp.

Back up and take another picture. Perhaps you can place a mirror the size of the window behind the lamp on the right. Top at the same height of the window. You can add drapes to the window and the mirror and balance the look.

Square. The other will be tippy. Ask me how I know...