It's a trap. Soon as the Marisas pull the feed close enough, the Reimus will jump on and start eating. Naturally, that will anger the hard working Marisas...who open their mouths to protest such uneasness. Whoosh, Reimus are Mr. Birds.
The darker food pellets are apparently high quality, while the rest of them are pure shit. Not literally, but you get it. The possible scenario I'm imagining is the Reimus getting a taste of the good stuff before knocking the food down from that plate-thing (too intelligent maybe?) and they keep on rambling about "amashing shwee-shwee" and "habbinesh", and when the marisas get to taste the food, obviously theres no good food left, so they rage at the reimus for being "shitty shcum -da je" and "uneajy wiars -da je", and then they proceed with the magnificent punishment. This is just what I imagine is about to happen, it may be wrong, but still, it fills me with happiness! -da je!
I personally would like to think that this is a perpetual scenario. The Marisas would all let go of the ropes as soon as the plate touched the ground and scurry over to the food alongside the Reimus, never actually managing to reach it before it gets pulled back up by uneasy mister gravity, repeating the process until they get too tired to keep doing it or die from starvation or kill each other for being scum or something.