After you posted that, I went downstairs and checked the authentic one we have in the cabinet, mine too has that.
After checking that, I went to further inspect my glasses received; 6 of them are perfect lips, all with laser etching; 6 of them have minor raised notches, like you said, and all with laser etching.
I didn't know how to check for the laser etching, I just knew it was working in the only one I've drank out of so far. After looking at the authentic one I saw it visibly and went to check my other ones. I'm not sure if you guys just got a bad shipment but half of mine are flawless and half just have the slight raised notch on the lip, which really isn't that big of an imperfection in my opinion... Still ended up with 6 perfect ones for around $25!