There are advantages to using a motor-generator setup as a transmission. The main application is in diesel locomotives, where the diesel engine drives a generator, and a geared electric motor is on each axle. The advantage there is that full torque can be applied to the wheels when the locomotive is stopped, and no huge transmission or clutch is required as the train speeds up. I think this system has also been applied to ships. This was also one of the advantages of steam engines.

For bike use, it would seem to be fairly pointless. Your legs can already generate full torque at a standstill, unlike a diesel engine. You really don't need or benefit from a stepless transmission. Motor-generator sets are normally heavy. On a locomotive, they need the weight for traction anyway, but on a bike, nobody wants to throw a few extra pounds on there. The bike in question shows both motor and generator to be very small, but there's no guarantee that they could be built that small, especially considering the slow speeds they would work at. The regenerative-braking feature would be handly only in certain situations, and even there, the extra weight of a battery might offset the gain from the braking. There's no reason you'd need the appliance styling, but the style is probably the starting point of this concept bike (ie, it's an exercise in styling, not an exercise in bicycle transmission engineering.) Small electric motors and generators are not normally that efficient, and just a small percentage loss in power would lower your top end speed as compared to a conventional bike.