I think the part near the camera for that corridor branches to the right as well given how the wall angles off.
Excellent catch on the stepping down at the far end! What I like about this is that it adds to the idea that the decks don't need to be level from bow to stern. The examples so far seen are:
Bridge = you step down into the central area.
Engineering, S2+ = that 2nd level including EMM are only 6 1/2' above the deck, which means entry from that deck you'd have to step down into them.
Long straight corridor = deck steps down at the end.
and in TMP
Airlock to the cargo/flight deck is a few steps higher necessitating stairs or a ramp.
Variety, that's the TOS Enterprise