What happens to photos on snap.as after delete

I know write.as and snap.as goal is to be privacy focused products. I would like to know what happens to content after deleting them. Specifically in the case of snap.as what happens to photos I uploaded and after I deleted?

Is it gone once and forever? Is a backup kept for a while? Is the content server side encrypted?

hope I get an answer from @matt as I assume he is the only one who could know