No it doesn't has any escrow feature yet. Every time you visit a link to a satoshibox uploaded file, it says somewhere on page :
"We are not responsible for uploaded content. Bitcoins goes directly to file uploader, we can't provide any refunds."
I think also it will be hard for the site owner to judge if the file was delivered as with promised features or not if you encountered with some problem where you downloaded the file not as expected or promised by the seller.
Is satoshibox is legit or not?