Island 8

All our machines, so far, have had boxes going to the left as far as we please. But that seems awfully asymmetrical! Why can’t we have boxes going infinitely far to the right as well?
Mathematicians like symmetry and so let’s follow suit and now make all our machines symmetrical. Let’s have boxes going to the left and to the right.
But the challenge now is to figure out what those boxes to the right mean.