It's quite sad indeed, and it is needless. To not feel jealous, you only need to do two things.
1. Keep in mind that as rich as these kids are, they will never attain the wealth that Mark Zuckerberg has, and as rich as Mark Zuckerberg is, he will never attain the wealth of Bill Gates. So even when they try to make other people feel small, there is always someone much, much bigger than them. And what does Bill Gates do with his money? Helps starving kids in Africa. lol.
2. Live a fulfilling life. Admittedly, this is easier said than done. But when I see a receipt scanned like the one in this thread, I don't feel jealous of kids living large, I feel sorry for kids whose lives are so meaningless that they need to try to validate them by spending obscene amounts of money and posting proof on the internet. I can remember being that insecure, and I can remember that acting out like that never made me feel any better.
Before I read this thread, I had never heard of Saint-Tropez. Wikipedia has a picture with a bay and lots of beautiful sailboats. I wonder how many of those kids sail, or play soccer, or kite surf, or backpack, or do any of the hundreds of things that I would do if I became far less wealthy than they apparently are. I hope they do, and at the point I imagine they'll be too busy really enjoying themselves to bother posting receipts on the internet,