an Image/Visual is a mental representation of some object, event, or pattern.
The human brain will constantly categorize different things that you encounter in your life so you could distinguish between one object/event with another.
For example, how can you distinguish which one is pencil and which one is an eraser? The answer is that your brain created some sort of image that stored within your memory about the different image that each objects have. So when you need to take a pencil, you could recognize which object that you meant to take.
