I would tip the white IKEA shelf and use it for the TV and remove what the TV is on, or use the black piece in the empty space. Mount TV above on the wall. It's too low as is. Well we need measurements. Some pics the white piece looks more substantial. Which ever works put one in all the wasted space between the sofa and the window, put a lamp on it, kids can use it to hide toys still. I am not comfortable with all the semi private glass on the door to a guest room.

The curtains on the windows are negated by the large expanse of glass opening to the hallway!

Maybe a lightweight curtain, with opaque material, that covers that whole wall and can be stacked on the left side when not needed. At least your guests would have some privacy.