Depending on where you live Twix packaging has an end like this, which gives you a top of the package to orient yourself to. But that’s besides the point because the ad expects you to not think about it too hard and just accept a left and right twix.
Hold it in your hand out in front of you with that top side of the wrapper in view, the left Twix is the one that has a bite taken from it.
Open that end and place it (still containing the two Twix bars on the table) pick it up again and hold it so the top side is facing up and slide out the Twix on the left to eat. It’s the one that is on the side that is whole.
But that can’t be the joke because there is no inherent orientation to twix bars, so there cannot be a “left”
Depending on where you live Twix packaging has an end like this, which gives you a top of the package to orient yourself to. But that’s besides the point because the ad expects you to not think about it too hard and just accept a left and right twix.
Hold it in your hand out in front of you with that top side of the wrapper in view, the left Twix is the one that has a bite taken from it. Open that end and place it (still containing the two Twix bars on the table) pick it up again and hold it so the top side is facing up and slide out the Twix on the left to eat. It’s the one that is on the side that is whole.
The wrapper is not symmetrical. You can consistently define a left and right bar of a given Twix in an unambiguous way.