I noticed that
http://tasvideos.org doesn't return a Content-Type header while the rest of the site does:
$ curl -s -I -X GET http://tasvideos.org
HTTP/1.1 200 OK
Date: Tue, 02 Jan 2018 20:25:06 GMT
Server: Apache
X-UA-Compatible: IE=edge;chrome=1
Last-Modified: Tue, 02 Jan 2018 20:20:06 GMT
Accept-Ranges: bytes
Content-Length: 19712
$ curl -s -I -X GET http://tasvideos.org/711M.html
HTTP/1.1 200 OK
Date: Tue, 02 Jan 2018 20:28:11 GMT
Server: Apache
X-UA-Compatible: IE=edge;chrome=1
Last-Modified: Tue, 02 Jan 2018 18:36:28 GMT
Accept-Ranges: bytes
Content-Length: 227115
Vary: Accept-Encoding
Content-Type: text/html; charset=utf-8