picture won't delete

I have deleted all images from my camera and formatted memory.
When I turn the camera on a previously taken image appears for a couple of seconds.
It never shows up in my pic count.
I'm curious as to what caused this but more importantly how do I erase it?

Thank you

What kind of camera do you have? That'll help us figure out whats goin on. :) I know on my wife's Nikon P&S, you can choose an image that will pop up as you turn the computer on. You might have set an image to do that on your camera.