Does the visible sign warn of two dangerous turns, the first to the right and the second to the left?

No. The visible sign is A-3 'Dangerous bends – first to the right'. Under § 4 para. 2 of the regulation on road signs and signals, it warns of dangerous bends, the first of which goes in the direction shown on the sign, here to the right. The sign does not say which way the next bend goes or that there are only two bends, so you cannot conclude from it that the second bend is to the left.