There is a possibility that you have noticed a square barcode on the business cards and other cards. In the QR code, there is a pixelated code and is designed in a square shape which helps the users to download the applications, can get a restaurant’s menu without any contact, and also help the users to promote the items and deals on the social media or website and much more.
Source: https://blanchektechnologyhub.wordpress.com/2021/05/28/barcode-basics-why-you-see-it-everywhere-and-how-to-scan-it/