These aren’t yours… Reverse image searching can do wonders.
Why are we meant to credit you? For sizing? Because… Anybody can do that.
“Oh, haha, lookit this background I made! Hehehe, nobody will ever be able to tell how diiferent the art styles are from one peice to another…”
Oh, wait… That’s what came when I looked up “Anime Bedroom”.
Here is an example of a background I made:
I used clipart. But I didn’t take a already-existing thing and use “Simple Image Resizer” on it.