In combination with the header mode it makes sense that you as a visitor can not interact directly with the video - since the nx-YouTubeBox can only add the video from Youtube to the page and no direct access is possible, you have to be a bit more "creative" here. The BlockLayer puts a (optionally transparent) layer over the entire video and prevents visitors from clicking directly on the video.

A nice side effect of this option: the block layer allows additional design options - so it is possible to provide it with an "Inner Shadow".