u/Comfortable_Car_3768

Why doesn't this work? I'm trying to compact my wool farm and trying to figure out layout but iv seen in tutorials the observer dispenser and redstone dust placement and that is the same(there is redstone dust on top of the hopper behind The Observer and underneath the hopper minecart which is correct placement in all videos I've seen) but the Observer doesn't seem to activate the Redstone when it's on top of the hopper is there a reason for this or a way I can come pack this design like this still to make it work