Can someone explain to me how staking with Kiln works?

I just saw a Twitter post from the official Ledger account that you can now stake your ETH with Kiln without losing custody of your ETH. I am not understanding how that would work. They say that you still own your keys and the ETH does not move, hence why you need at least 32 ETH.

Can someone ELI5 to me how that works? Do you “rent” their validators and somehow assign your ETH to it? ARE THERE ANY RISKS that someone using this platform should be aware of that would cause partial or total loss of their ETH?