It's just a kind specific to image feeds. It allows multiple images per post and tag users in the image.  

 how does it support multiple images in a post? I only see an "x" tag (duplicated) 

 Multiple imeta tags 

 multiple imetas 

 Multiple images (imeta info for each), tagging people in images, geo location (I.e. the typical instagram feature set) 

 🤔🤔🤔 I think I might have deployed a version with the publishing commented out 

 Publish button reacting... 🤷  

 Yep, wake us up when this shit is working.