It's marked as "Too broad", but I don't understand why.
There are either too many possible answers,
I hope not, it's a question about a really specific function of a particular site..
or good answers would be too long for this format.
I'll take even an overview, like what methods/technologies are used, doesn't have to be a fully commented code. How do I edit it to make this clear?
Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs.
I'm really lost here, I can't narrow it down, if I could I wouldn't even be asking it in the first place...