A Guest Nook
I'm not sure what you'd call this besides well, a guest nook, because that's all it really is. A bed in a corner. For those times when the guestroom or the floor of the loft are already claimed (since friends & family tend to be overnight guests from out of town).
I made just enough room in the corner of the office to fit my old twin mattress, bought a small bed frame, and used a bedspread & some pillows from the closet (along with striped pillowcases found on clearance...every bed needs those, right?).
The picture ledge & frames had been sitting in a closet, too, and the old filing cabinet next to the bed now leads a double-life as both nightstand and office storage. The 'guest nook' has already been put to good use a few times and is proving to be a cozy little spot!
(bottom pic borrowed from my instagram feed)