The uploaded image and the original are the same dimensions and quality as far as I can tell (Filesize is a bit smaller from what I see), so I assume the mismatch is not a problem?
@Kamuro that's an automated message from BE98's bot. Make sure you're using the Bookmarklet when you're uploading from twitter (in the case of multi-image tweets like this one, use the second one in the page I linked, "Batch to Danbooru"). We try to keep the files as the artists distributed them for multiple reasons, and in the case of Twitter the :orig picture is the best out of the variants distributed by that site (including :large, etc). The bookmarklet will pick the correct picture to upload for you.
