They explain it in the first paragraph.

There’s no more to it than the name essentially. A scammer gives an address and says that if you send crypto to that address, you will receive double the amount you send back. Then they keep the money you send.

I’m sure they dress it up, maybe they actually fulfill a few or they have shills that claim they did, but it’s really not more complicated.

It’s classic “if it sounds too good to be true…” stuff.

It's so dumb you probably missed it:

> The scam takes many forms... promising to double Bitcoin sent to an address... But of course, the promised doubled crypto never comes, hence a scam.