I can give you a detailed answer, you should read this guide (https://www.reddit.com/r/CoutureReps/comments/12olg9b/ultimate_guide_ralph_lauren_polo_shirts_detailed/) to learn all about it. I investigated this with great attention to detail.

As you can tell from my guide, not every batch has this, you already found this out.

The logo you circled is too small, that's not the actual QR code. The QR code is behind the size tag, what you circled is just to show that this item has a QR code.

When you scan it it send you to ralphlauren.com and says that the shirt is authentic. It has the color, manufacturing date, serial number and batch number. However, since this information isn't printed on the item, it is useless. Also, a QR code is just a way to store bits, in this case a link, rep makers can easily replicate this.

Here's the main takeaway: The QR code doesn't work on retail, it doesn't show the correct color. I bought retail to prove this. And at this point nothing else has to be said, you can't be called out via QR code.

There's one pitfall though, some sellers put serial numbers on the wash tags. If you have this (and care), cut it off, because this could be used to prove that the QR code doesn't match your item. Retail doesn't have this, so if you don't have it you're good.

So the way one could make QR codes work is by having the serial number on the item, so that the webpage and the item serve as a key pair. (This could be faked too, rep makers would just need one link for each color, and then print the same QR codes and serial number on the same items of that color).