How to identify if wood-framed wall is load-bearing?
“Load bearing” means it’s holding something up. It doesn’t need a wall DIRECTLY below it. Often we’ll provide a beam or a series of oversized joists to span an area directly below a bearing wall. Not all bearing walls align all the way to the foundation. 

At a minimum, it appears the wall is holding up the ceiling joists to the right side. The OSB board on the ceiling joists is a clue that something is resting on the ceiling joists...perhaps a mechanical unit. 

It also appears to have some kind of roof structure spanning PERPENDICULAR to the wall. It’s difficult to see if it rests on the wall. (I say roof structure,because there is insulation exposed.) 

I’d get a professional opinion before you tear it out. Maybe you’ll need to add a beam to replace the wall.