When uploading https://farm9.staticflickr.com/8373/8413677741_e1cbafaa06_o_d.jpg (from https://www.flickr.com/photos/44112235@N04/8413677741), Special:Upload gives
This file contains HTML or script code that may be erroneously interpreted by a web browser. See the FAQ for more information.
but the API gives
This file might be corrupt, or have the wrong extension.
(api-error-verification-error) which is not helpful, especially given that the file is probably entirely valid, it just has a risk of running afoul of the buggy MIME type sniffing logic in in IE 5-7.