Board Thread:Support Requests - Designing Your Wiki/@comment-4988763-20180330201637/@comment-168424-20180330233646

Go to Special:Preferences and check what your editor is set to on the Editing tab page. Either way, only preview on the Source editor is really going to give you an accurate look (although it tends to be too narrow) at the final page formatting and layout.

The only difference I can see between the 2 pages is the video is missing from one of them in the "Fun Facts" section.