I was thinking the same thing, those eyes they put on it made the peepers useless as the bird could not see.IMHO, the reason the hen would sit all day is because they put the googly eyes on. The peepers are a specific size and shape, I am assuming so the hen will still be able to see enough peripherally to walk around and eat. The googly eyes increased the "lens" size by almost double, probably blocking too much of her vision. (You can see the size of the peepers as a shadow thru the googly eyes when the sun hits them.)
My hens, OTOH, are absolutely fine with the peepers. They can still do everything they used to do, and can forage for bugs, dust bathe, etc...no problem.
I think the hen in the video would've been fine had they not futzed with the peepers. Now, having said that, way smaller googly eyes would be ok & really cute! lol...