cover the windows in the bonus room
Fake a basement window maybe? Could be a great ambient light option.
screens used as headboard and window covering
window coverings; could be thermal barriers in winter - open to expose a view through sliding glass windows...
screens as a semi-headboard - also a great option.
uses: windows, kitchen cabinets, room dividers and more. The key: Don't obscure them with furniture or accessories — you'll block the light that filters through and mar their austere beauty.