My internal thoughts are verbal and don't see pictures as a normal part of my inner though process.
When someone says "imagine a pink elephant in the room" I don't see a pink elephant, but instead have an inner dialogue to the effect of "ok, so there's a pink elephant in the corner." I may also recall an image of an elephant, but it's not pink and it's not really in the room.
When there is a concrete thing that I have a memory of ("picture a squirrel", specific things from holidays, etc.) I can see flashes of still images from those. I don't see a generic squirrel, but a specific image/memory of a squirrel I have seen.
I have general placement/shape awareness but not so much colours or other specific details. I can infer things like colour from context, or have a thought to the effect of "that building was white" but I don't really see the building as white.