How to get information about collage pictures?


#1

Twitter has announced this new collage feature (upload up to 4 pictures on one Tweet).
Where and how is “stored” this collage information as, when I call https://api.twitter.com/1.1/statuses/show/448927844979056641.json (Tweet from Danny Sullivan https://twitter.com/dannysullivan/status/448927844979056641/photo/1), I only see one media entity and no extra information about this collage ?
thx