By using an app called Share 2 Steem, one can automatically make a Steem post where a YouTube video is embedded, or a Twitter tweet or an Instagram post included as the content. That is, those three mainstream social media outlets can be used as Steem front ends. Since the Steem blockchain only stores text, using Share 2 Steem does store copies of photographs or videos on any decentralized storage. (It would be cool, though, if it used something like IPFS to store the pictures or videos as well. If it worked like that, the app would be extremely convenient for YouTubers or Twitter or Instagram users as a backup storage in addition to enabling them to tap into the reward pool.