"Tips" were effectively bids for service under the old model, as they were paid before the service was performed and determined whether a driver felt it worthwhile to accept that order. Now DoorDash will have to dynamically figure out how much to charge the customer to both interest drivers and meet this minimum pay requirement. I'm interested in seeing how it turns out.
The press release says they're paid "after checkout". I assume that that means immediately after payment of what appeared to be the price, but still before receipt.