MultiBID does not utilize Proxy bidding.
However, for reference we have described what it is below.
Proxy Bidding (also known as Automatic Bidding) – is when an automatic bidding system makes bidding convenient so you don’t have to keep coming back to re-bid every time someone places another bid.
When you place a bid, you enter the maximum amount you’re willing to pay for the item. The seller and other bidders don’t know your maximum bid. Bids are placed on your behalf using the automatic bid increment amount, which is based on the current high bid. The system will bid only as much as necessary to make sure that you remain the high bidder up to your maximum amount.