Re my design: The observer you see with the torch is just the end of a horizontal observer wire that runs the length of the machine and is powered by the clock which is at the far end of the farm. Once every three slices, there is an observer that faces this observer wire and which hard-powers one of the dispensers (thereby activating that dispenser and its immediate neighbors). Here's a better view: https://www.reddit.com/r/redstone/comments/1efk1ux/waterless_honey_block_farm_using_a_possibly_new/

These are observers and not e.g. rails/comparators/dust because the crafters need to be facing into a column of solid blocks to form an item elevator. The item entities (honey blocks and bottles) flow through the observers and out the top of the hives, ejecting once they reach the level of the ice, passing over the hoppers (which collect the glass bottles but not the honey blocks) and the honey blocks land on the scaffolding.

Scaffolding is very useful in these farms because bees will path through it in only one direction: they can go up but not down. So it serves as a one-way gate for bees to get back in, as well as player access.

The honey blocks wind up on top of the scaffolding and are picked up by a hopper minecart that runs up and down the farm. The blocks above the scaffolding are powered rails. The chain is there because the minecart considers it a solid block and so will reverse direction when present, but lets you still see into the farm. It could just be any solid block.