I think the properties on this object should be of the same type, not one content and one oembedView. I think it's preferable to emit the Content instance and the oEmbed instance, and not views. Anyone receiving the event should decide what sort of view they want to use.  If the receiver is this AttachmentListView, he can get the appropriate contentView for that content or attachment. But other objects handling the event wouldn't be tempted to reuse the focusedAttachmentView and hide it or show it accidentally, which would affect the display of this guy.