I do know that "barrows" can also be two wheeled with two peg legs, or four-wheeled, but at that point I really think it's a hand truck. And I think this is a little battery-powered dump truck:
Here's a similar one, petrol-powered:
MUCK-TRUCK POWER BARROW 1/4 tonne capacity, Honda engine, 4 wheel drive, 3 forward/ 1 reverse, Unleaded petrol, Very good condition, £ new ...
Because I had no need to know, I wasn't aware of these, but I like them! A Canadian site says "Since 1993, Muck-Truck has evolved to become the world's most popular power barrow and motorized wheelbarrow," and the company's slogan is "It doesn't cost the earth to move it." Nice. So here's muck-truck Canada.
But they are hand trucks, and not wheelbarrows, in my sorting and labelling world.