Look at the hinge picture. See how the two hinge pins are parallel? Now imagine the blades turning 180 degrees. The hinge pins will now be at the "opposite" angle to before, despite that the blades are symmetrical so identical at 180 degrees to 0 degrees.

So at 0 degrees, increasing torque will, say, increase pitch of the "right-hand" blade while decreasing pitch of the "left-hand" one. But at 180 degrees it will be the opposite. This has the presumably beneficial effect of allowing the craft to climb by simply increasing rotor speed steadily (it will "wobble" a bit but in a spiral fashion which will let it climb without too much inefficiency). Put another way, this means that increasing torque at 0 degrees but decreasing it at 180 degrees allows an asymmetrical pitch to be maintained at a rotational speed which can be seen as constant (over the long term).

In other words, your intuition falls down because the mechanism is not as symmetrical as your brain wants it to be at first glance. Symmetry is an intuitive and attractive for mechanical systems, but it is actually limiting in many cases, and this is a great example.

The hinge that connects each blade to the rotor is angled with the same pitch, but on opposite sides of the rotor, like this:

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When the rotor applies more torque than the current angular momentum of the blades, the blades lag behind the central hub, pushing them the same direction against their hinges. On one side, that increases the blade pitch. On the opposite side, it decreases the blade pitch. The motor could also apply a slight braking force, to pitch the blades in the opposite direction.

The flight computer determines the correct timing at which to apply more oomph to the drive motor, which translates to the same effect as a mechanical swashplate due to the angled pins. The total energy imparted to the blades over a single rotation remains the same as with a motor operating at constant torque.

One disadvantage is that you will need a motor that is capable of applying more maximum torque, because you won't be running it at 100% all the time, but with a sinusoidal power level that will go both above and below that steady level. The other disadvantage is complexity in the computer controlling the motor. The advantage is mechanical simplicity.

Didn't you read the article and watch the video? There is a sinusoidal signal added (i.e. up and down) that matches the rotation of the blades and controls the hinges on the blades. So the signal can be high when the blade is on one side of the vehicle then low when the blade is on the other side. Or vice-a-versa if the control system wants to go the other way. Both blades tilt the desired direction when they are on the desired side of the vehicle. The video is quite good and shows the blades hinging different directions on different sides when the signal is applied.

There are two motors.