The view ns_media_browser provides a new view for the media popup, where you have several exposed filters and sort options. One of them (tags) is an auto complete field. This doesn't seem to work well with the autocompletion of the form. When you start typing in the tags textfield, the form auto submits directly and you'll get an error.
The patch disables the auto submit for that view. Since it doesn't work properly together with auto complete, it makes no sense to keep auto submit.