You are right to be confused. "Social sharing" came out of Snapchat marketing department when it became obvious you couldn't build a long-term business on a product that was synonymous with sexting.

Snapchat's core is still revolving around soft erotic eye candy that's developed into a cottage industry at this point http://www.bloomberg.com/features/2016-arsenictv-snapchat-in... Now that they've got your attention there, they are bringing in media partners like BuzzFeed, Entertainment Weekly and celebrities http://www.bloomberg.com/features/2016-how-snapchat-built-a-... to fill up your feed with a stream of bite-size updates.

Peer-to-peer ephemeral messaging is no longer emphasized in the app, they are building a media destination to divert eyeballs away from TV, YouTube, Vine, Facebook or Twitter, in that rough order. Referring to ephemeral social messaging at this point as akin to bringing up Yahoo! as a directory of web links.