It is us, or is this one particularly creepy? The message is easy enough to follow - there are plenty of people walking around us who are putting on a fake smile. Some of them are doing it because they want to please us. Some of them are doing it as a show of defiance. And some - perhaps quite a lot - are doing it to hide the fact that they're actually very sad.
Nobody wants to live in a world where you're required to put a brave face on all the time. If there was such a thing as a smile shop, it would make all smiles redundant. So, if you are feeling a little blue, talk to someone. Don't throw money at the problem and get a fake smile from it as a result, like these people do. Take some time for yourself and work on getting your real smile back. Remember that it's OK to not be OK.