"Pixel-perfect duplicate" ah yes, a 1.11 MB image is a pixel-perfect duplicate of a 199 KB image, sure.
Look closely at the image, it has JPEG compression all over even though it's supposed to be a PNG. This is a duplicate completely identical to its parent post.
This can happen for lossy-lossless images. They're different file types so the sizes don't matter except in exceedingly rare circumstances. Regardless of the size and type, if it says pixel-perfect duplicate on the bottom of your screen in the uploader then it's an inferior copy and generally shouldn't be uploaded - and if it is, duplicate is in the name, it should not be the parent of the existing post.
"Pixel-perfect duplicate" ah yes, a 1.11 MB image is a pixel-perfect duplicate of a 199 KB image, sure.
The others explained things well enough, but if you still don't believe it's a pixel-perfect duplicate, you can check for yourself by putting the image URLs in https://duplicatebooru.zipfiled.info/. If the first row in the second box says "yes", then the pixels are exactly the same.
The pixel-perfect duplicate tag is usually applied by a bot. Since it was added by another user, I double-checked them using the tool and confirmed the tag applies.