That's my plan at this point. A nice high-res B&W movie, say 1024 by 1024 pixels.
It starts with an image of the probe, showing it next to a planet. The planet shows lights, suggesting a civilization. Then the image zooms out to show the rest of the galaxy, and zooms into other planets that have similar lights.
Next, back to an image of the probe and a planet, showing slow (light-speed) signals between the two. Then it zooms out again, and should faster signals.
But here's a question: Why do the pixel width and height have to be prime numbers? I know Sagan did that, but I'm not sure it's necessary. If the first frame is a square of rectangles along the outer borders, I think that might clue in the receiving civilization.
How would it help if the image were 1009 x 1009?
If it was something like 1024 x 1024 we would have to try lots of possible combinations to decode it. 512 x 2048, 256 x 4096, etc., though not too hard these days. The prime numbers allow only one solution. Still have to figure out which side is up though.