What if all matter in the Universe is actually shrinking, then a shrinking observer in the Universe would see everything else moving away from them. Giving the impression of an expanding Universe!
Sorry, I don’t install plugins into my browsers (especially not those that can run code), so I cannot see your thing.
But we can measure that the stuff around us is moving away from us. How can that be shrinking?
Sad fact: in some billion years the living beings in the universe will no longer see any neighboring galaxies, so they will think what they see is everything.