If your video player is buffering the content between 1:30 and 1:35, it will issue a request for that chunk of the file. It will get a 206 in response. The request is successful because you got what you asked for.

That said, I wouldn't be surprised if I sat on the wire for a video player and saw a stream of 200's instead of 206's. There are plenty of times people do not bother to exercise the entire HTTP spec.