Nah, the pale outlines are because of extreme JPG compression. Which is what I don't like about these. It's a fancy idea, but with these small, undetailed, super-compressed photos, you might as well just convert the whole thing into pixel art and try your best to replicate the realism by hand. That'd be a bit of a challenge, too.
If you're not fond of that idea, I suggest you use a more interesting base photo. Like... people in a park. Try to pixel a character so it looks like it's sitting next to real-life people or something. That'd be more fun to look at.
Ah well, as long as you enjoy it. I'm just saying, I don't see much of a point in showing it off.