It's almost certainly the code that changes. That's easy to program and is very common in apps that produce scannable QR codes that they don't want duplicated,

It's almost certainly the code that changes. That's easy to program and is very common in apps that produce scannable QR codes that they don't want duplicated, that will only work for the next e.g. 60 seconds. Any animation that could reliably be picked up by a scanning camera would necessarily be quite visible to the user. Just think of how QR codes often don't even work until you increase your phone's brightness, and they're as high-contrast as you can get...