A form of resizing which makes a source image smaller.
There are typically two cases where you will see this tag used:
An image is downscaled from the source.
md5 mismatch will also typically be tagged in cases like these. If an image is tagged downscaled and md5 mismatch, and there are no edits or revisions from the source, it is treated like an image sample.
This tag may also apply when the original image is so incredibly large (filesize) that it simply cannot be uploaded. (There may not be any actual examples of this.)
An image is downscaled from its parent image on another website by the artist or someone else.