Advertisers spend millions of dollars to collect data on you, research the data, and target you more effectively with AD's based on who they think you are, or what will appeal to you.

SocialPortraits_SponsoredBy : An Instagram account for said advertisements, collected and curated over a period of time which amass to a social portrait of an individual. This curation [October 2016] is a self-social portrait — at least according to Instagram's "sponsored" posts. 

IG: SocialPortrait_SponsoredBy