Keep in mind that movements in forms are stylized.
That movement teaches many things. Consider...
You are performing a high block and an outside middle block at the same time, so it's being used to teach simultaneous movements, as opposed to individual movements.
The classic example is using this to block simultaneous attacks from different directions.
Beyond that, application becomes a matter of detail and circumstance.
Consider a high kick. In the picture you posted, the right arm could be deflecting the kick upwards, while the left is delivering a hammerfist to the groin.
Similarly, this can be used to counter a high punch and set up a take down:
Shift the body position somewhat so you're perhaps a bit more squared off to your opponent, both left foot forward.
Your opponent throws a left hand to your head.
Your right arm moves up (as in the picture) but let's do it with an open hand so as it rises we can grab the wrist.
At the same time, your left arm moves out and under your opponents arm. You may be stepping in, too, depending on the exact body positions. You can hammerfist the ribs on the way in, if you like.
But consider the body positions now. By virtue of a bit of footwork and twisting the body, you can throw your opponent.
Forms show principles. Applications are endless...