That's a broker who works exclusively for the person who's looking for a house.
Traditional brokers work for the seller, even though they show buyers around.
The differences are crucial. A broker who works for the seller is duty-bound to negotiate the highest possible price for the house. Buyers often don't realize this. As you chat in the broker's car, you may disclose which house you love and what you'll pay in order to get it. That information goes straight to the seller, undermining your bargaining position.