I do have the "second visual canvas" people here are talking about, but the thing about mine, and I haven't seen anyone say this yet, is that I don't have full control of it.
For example, I have a memory from childhood of visualizing a yellow bucket, and it showed up in my mind's eye with big cartoon eyes. I tried to delete the eyes because I just wanted a normal yellow bucket, but they kept coming back.
Also, when reading Harry Potter as a kid, Severus Snape always showed up in my mind's eye with the head of a crocodile. I remember telling my brain, no, he's just a guy, just give him a normal man's head, but it never worked. Even now when someone mentions Severus Snape I see him with the crocodile head.
Anyone else, or am I just nuts?