The observer block was introduced a while back, and I was never able to make it work. Now, I saw someone do a tutorial on how to observer blocks, and for me the observer would never send block updates with redstone pulses. Am I really not doing this right? I know the block only sends a one second redstone pulse, but that never happened in my case. (I am on 1.14.1)
You have the block back-to-front.
This side of the block should be facing the object you are trying to detect an update:
The redstone signal then travels in the direction of the arrow on top, to the back of the block with the red dot.
Think of it this way: the Observer needs to "see" with its "face", in order to "observe" an update.