Yea i didnt meanpicture like visual images, but mental images, the sort of nonvisual images your consciousness perceives, when you see or hear something.For example when you hear someone screaming a certain way, you might get an image of someone being in urgent need of help. Without this image attached to the screaming(or everything else you perceive) the noice would be meaningless static, something thatnew born babies are experiencing.
What i think the consciousness is observing are this sort of images. Even the sounds you hear with your ears are these images, same with visual perceptions. Take the ames room illusion as an example, ifitwas the actual outside world youperceived,there wouldnt be any illusion, but because you are using an already existing image of a room in your perception, you see the people changing sizes,evenifyouknewthatits justan illusion.
Naturally the images are created by stimuli coming from the eyes,mixed with your already existing images and some of these images are so deeply rooted, like the image of a room, that its not altered by external world, instead the externalworld tries to fit itself to this image.