True, if it works that's what you really need.
I think of eddies in the spaces between as little whirlpools of lubricant. They push back against any pressure to pass. When I used to do whitewater canoeing, you'd see eddies behind rocks which stuck out of the water. If you maneuvered your canoe behind the rock, pointing upstream, it would stay put there with water rushing either side of you. You could sit there and eat lunch if you wanted -- we sometimes did.
When the water passes the rock, there's basically a hole in the flow behind the rock. Water from immediately downstream tries to fill that hole, and to do that it has to flow upstream toward the rock. That's the eddy. It's water that is flowing opposite the main current direction, and that's what keeps you parked against the rock.
So eddies in a labyrinth seal must be doing something similar -- the flanges of the seal are acting like the rock, and behind it in the pocket there must be a counter current pushing against the leakage of fluid. Maybe they put several of these in a row to reduce the leakage to nil.
Well that's about as far as I can imagine it working anyway.