Build pixel art on the 20x20 grid then simply pull the lever to send it to the big screen.

Something I tried to build years ago but was never able to and hadn't tried since observers were added.
Thanks to Mumbojumbo's video where he built something similar it gave me the last piece I needed to actually read the image which was how to take and separate observer lines.

IMPORTANT NOTES BEFORE USE:
1. Always make sure the system is off while you edit your art, otherwise it will invert whatever pixels you changed you can fix this by replacing the broken pixels while off, and removing them while on, this will re-invert them back to normal.
2. Be very careful not to break the observers on the scan platform, not only are they very difficult to replace (involving placing it 3 or 4 blocks high and pistoning it down and having to piston the final piston into place before you can finally get it back in) but it can invert whatever pixel was broken.
3. This contraption is massive and lag inducing be warned. (at least on my poor little lap top)

If you have a better computer and you try this out please let me know how it worked. I'm curious how well it works and how it looks when not being dropped to 5 fps.