is this legally alowed?

Currently I'm studying a master's in Accounting & Control and I wonder if Nvidea violates a contract with the customer. Cause under IFRS 15 a performance obligation is a promise in a contract to transfer a distinct good or service to the customer. The customer, in turn, provides consideration in exchange for that good or service.

However I do know that IFRS and IAS applies only for European countries. So how does it work for the United States where the parent company is located?