Why does this duplication thing happen when I save?

By DapperMuffin — January 02
Total Replies: 0
The first link is what my art looks like while I'm working on it, and the second one is what happens when it downloads or when I try to preview it. It doesn't happen every time or and it isn't on a specific layer or a specific .pixel.
https://sta.sh/01hwjgqeh3nw
https://sta.sh/0xlneqcqlud
Why does this happen and how can I fix it?
Edited January 02