You hadn't mentioned any marking only that Pirelli said they were "All Season".
My only surprise was that
1 - Pirelli did not mention an important selling point like the Mountain and Snowflake marking in their description.
2 - If the tyres were compliant why Pirelli felt the need to specify they were for "not severe" winter conditions when such tyres are generally required (in Germany) to be used in severe conditions.
Sources other than the manufacturer have confirmed the marking - that is all you need.