Why is the HasChangedOwnedEntities() method needed in the implementation of AuditableEntityInterceptor ?

[EnricoMassone]

Good evening everyone, I'm writing here looking for some clarifications on the AuditableEntityInterceptor class.

My question is related to the HasChangedOwnedEntities() extension method.
Is that really needed ?
Why the condition expressed by entry.State is EntityState.Added or EntityState.Modified is not enough to identify any entity which has been added or modified during the current unit of work ?

My understanding is that the purpose of the HasChangedOwnedEntities() method is to detect entities which must be considered modified because at least one of their owned entities has been modified during the current unit of work.
Is my understanding correct ?
Why simply checking the condition entry.State == EntityState.Modified is not enough to identify these entities ?

Thanks in advance to anyone providing some clarification on this.