I got a message from the system saying this pixel art needs to have a transparent background, but it does? It's outlined in white but that's only so you can see it more clearly but I don't see how that would make it "not transparent" anymore.

nope no preview with a background.
yeah this is a challenge entry.
there is no box anymore to check weekly challenge, but there was when i first submitted it (and i did make sure it was checked).
I will resubmit. Hopefully everything turns out okay.
Thank your for your help.