Here's a short video making a parallelism between quantum superposition and a 3D postcard with two portraits of the famous Mexican painter, Frida Kahlo, representing two quantum states.
At the start of the video below, the postcard represents an unmeasured physical system, in which two states are in superposition. In the video we see the blank part of the postcard, meaning that we haven't measured the states yet, which in this video are represented by the two portraits of Frida Kahlo on the other side of the postcard. When we flip the postcard, we make our first measurement, which is the manlike portrait of Frida. In a quantum system, the result is probabilistic and the probability of measuring a certain state is given by the squared coefficients in the wavefunction, as explained in the previous article. Then, the postcard is flipped again, showing the blank part and putting the two states in superposition. We are ready to make another measurement. The postcard is flipped once more and we measure the second state: the womanlike portrait of Frida. In a quantum system the second result is probabilistic, like the first one.
For a comparison with a quantum system in superposition, have a look at the following video which shows how an atom can be both excited and not excited simultaneously.
A final note: in the postcard case, the result is not truly probabilistic. As a matter of fact, if we were to know the variables of the system such as the angle of rotation of the postcard, its final position, and its angle with respect to our eyes, we would be able to determine which of the two "Frida-s" would appear as an output. Whereas in a quantum system, the result is purely probabilistic, meaning that there is no way to know the outcome until we perform a measurement. In other words, in a quantum system, there are no hidden variables (as in the postcard case) that determine the outcome. This is one of the weird aspects of quantum physics and one of the reasons why many people consider quantum physics counter-intuitive with respect to the macro world.
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