I usually do think in pictures. Although the pictures aren't something you can draw, but "mental colors" so to speak. More like abstract art. Perhaps even more abstract than abstract art, because with abstract art you use real colors and real strokes.
But on occasion I notice something bizzare that differs from all that. I might picture a real location I used to frequent at some point (so that won't be abstract art any more). And what is interesting is that said location might have nothing to do with whatever I am thinking about. For example, one of those times I was thinking about racial issues, I pictured a road by a pond in Moscow. What did it have to do with it? I have no idea.
Then there are other times when my picturing various locations can be more logically explained. For example, I was reading a fiction story about Russian prison, and it said that its windows were pointing northwest. My appartment in Russia also had windows pointing northwest. So I just pictured that whole story as occurring in that appartment.
Even if they didn't say northwest, I would still likely fill it with "something" from my memory. It just perhaps won't be that particular appartment. But some other familiar location.
Incidentally, even now, I notice that parts of that story I picture in my current American house, where windows don't point Northwest. So actually it is sort of jaxposition between (mostly) Russian appartment and a little bit of American house and a little bit of some other places.
I don't mean to say that I always envision things that random. When I think about the substance and I need to picture something to help me think, I would. But other times when I need a picture as a filler, that woul dhappen too.