Putting it all together: India Sumner (Callie's actress) and someone named Elsa Jean in 2021 related to The Fosters. But since the show ended in 2018, maybe it's a fan event, a convention, or a tribute. Alternatively, maybe there's a fan community or a social media post from that time.
Based on the specific ensemble cast you mentioned (India Summer and Elsa Jean) and the "Pure Taboo" style of storytelling from that era, the feature you are referring to is titled: puretaboo india summer elsa jean the fosters 2021