Is this a trick question?

Do you have ties (one on each side) fastened to the window frame? You mentioned a rod and curtains hanging but you did not mention having ties or tie-backs?

The outer edge of the curtain and or the rope and tassel used as a tie back are attached to the edge of the window frame or sill with a hook.

I think they're using a holdback attached to the wall to keep the curtains against it.

Have you tied them with anything? If you haven't they will just fall on their own. You need to gather each side up, secure with a ribbon, and determine where you want them on the wall. Measure from the floor up for height, and distance from window trim to determine this. Screw in a teacup hook on each side. Don't tie them too tight, but allow the gathers of the fabric a gentle 'swag'. Hang the ribbon onto the hook. I usually make an extra loop for the hanging part. Good luck.

thanks all for you help.