Is that the battery under the saddle? It is difficult to see if there are wires coming from it. The black rectangle on the rear carrier looks like seat padding for a child passenger with possibly a small footrest next to the hub.
Yes that is the battery. I first spotted the bike at the weekend and it stood out because it looks more like the bikes we are familiar with in the UK. The majority of the bikes in China are like my SLA one below.
With the girl sitting on it, the battery was hard to spot.
Back to the 'unusual' bike.
The wiring is also quite discrete. From the meter on the handle bars through the inside of the downtube and up the inside of the seat tube. It appears that the controller is also built into the seat/battery. I also can not see any wires leading externally to the motor.
Will have a closer look tomorrow.