Not just an image of you. Time is actually dilated. Gravity wells cause the same compression / stretching of time that traveling at the speed of light does. It's the same equation that says as you approach the speed of light time is compressed: near light speed you could travel to Alpha Centauri in one second, yet it would appear to me that you took four years to get there - you appear almost frozen to me during the trip!
This is the same effect as falling into a black hole. Once you reach the event horizon you experience the same time dilation as hitting light speed - it's instantaneous for you, but takes an eternity for outside viewers.
Here's an analogy, imagine you're sending messages once per second, but they take 1 week for me to get them. Once I get your first message, then I will get a new message once per second, not once per week. They're delayed, but the interval is the same. If you keep sending one message per second, but I observe that they drop to one per two seconds, I can only infer that either you've slowed down, or you are moving away from me, hence messages come less frequently. But with a black hole, the observed person isn't observed to be moving away and the distance / space distortion between me and the black hole never changes. Hence, the apparent slowing of a person who hit a black hole cannot be explained by the doppler effect. The doppler effect cannot occur for something that isn't moving.