A small window can be made to appear larger with clever positioning of the curtains – and in turn, it can make the room look bigger as well.
Hang the curtains from well above the window, and drop them all the way to the floor. Extend the rods past the outer side edges of the window, so that you can see most of it when the curtains are open. Place furniture such as a desk, chair or low cabinet under the window and top it with a couple of tallish items to lift the gaze to the window and complete the illusion.