Board Thread:Support Requests - Designing Your Wiki/@comment-33220655-20180503040552/@comment-9605025-20180504223724

As Fandyllic's reply implied, the file size and the image size are two different things. Image size referrers to the number of pixels (length multiplied by width). Typically, larger image sizes allow for "better" and larger images. The file size is how much storage space the image requires. There are various methods for storing the data so the file size depends on which method you choose.