After these signs, the maximum speed for a truck driver with a maximum weight not exceeding 3.5 tons is set.

Erklärung
The plate below the 80 km/h limit uses the passenger-car silhouette, whose covered class also includes goods vehicles with a maximum permissible weight not exceeding 3.5 tonnes. The truck in the question is within that mass limit, so the displayed 80 km/h limit applies; neither 60 nor 70 km/h is indicated.