My site calls Twitch API every two minutes to get stream data and caches it. If the stream goes down between updates, the preview image will show the generic 404 image.
My site has SSL enabled and when using SSL and the stream preview redirects to the 404_preview, it redirects to a non-SSL URL. When this happens warnings appear about mixed content.
An example:
https://static-cdn.jtvnw.net/previews-ttv/live_user_fredsauce-220x124.jpg?time=1455762882589
Will ALWAYS redirect to:
http://static-cdn.jtvnw.net/ttv-static/404_preview-220x124.jpg