وَلَوْ تَرَى إِذِ الْمُجْرِمُونَ نَاكِسُوا رُءُوسِهِمْ
If you could see when the guilty hang their heads. (al-Sajdah 32:12)
The second-person form does not have to be confined to one named hearer. It places any possible observer imaginatively before the scene: if you witnessed the guilty with lowered heads, you would grasp its gravity. This gives an absent event the force of a vivid address.
The grammatical form remains singular second person, while the rhetorical invitation can be general. Do not confuse the number of a pronoun with the breadth of those invited to imagine the scene.