piston is responding to a redstone block one blocks up.

The piston does not respond to the redstone block two blocks away, but this piston does. sticky piston also responds, but others (dispenser, dropper, etc.) do not.

Depending on how the piston's head is placed, the piston's head may remain. The piston's head cannot be broken, and if a block is placed where the piston's head is, as in structure void, and the block is broken, the piston's head is gone.

And if you break the redstone block, the piston's head is out, and if you put a block on top of the piston, the piston's head is gone.

何が起こると予想していたかは...:
No interblocking, so piston is not responsive.

実際に起こったことは...:
The piston works.

再現手順:
1. Place piston or sticky piston (can be oriented vertically)
2. Place redstone block one block above piston