I mean the overlay is not aligned to the "pixel grid" of the QR code. A QR code is made up of various squares, the size of each square depends on how much data is being embedded into the code. All of these squares have a uniform minimum size for any given QR code. I'm calling the smallest squares "pixels" because they are basically just a single pixel magnified enough to be properly identified by a camera. And the "pixel grid" I'm referring to is just a grid where each cell (or pixel) is the size of these squares.
In the image below, I've outlined a few of these squares ("pixels") to show their size and how some of them are only partially covered by the overlay image.NANY 2023 Release: QR Code Warlock
In the image below, I've outlined the entire area where the overlay covers some of these squares only partially.NANY 2023 Release: QR Code Warlock
In my opinion, QR codes would be more aesthetically pleasing if the overlay image snapped its dimensions to a multiple of the "pixel grid" size, so there are no partial squares showing.