The people were naked. It has been suggested that "licentious" or "unruly" would be a better rendering (Gesenius, Dathe, Rosenmuller, Kalisch, Cook), but the primary sense of pharua is "naked," "stript;" and of the licentious orgies of the East, stripping or uncovering the person was a feature (Herod.
2.60), so that there is no reason for changing the expression used in the Authorised Version. Moses saw that most of the people were still without the garments that they had laid aside when they began to dance, and were probably still engaged in dancing and shouting.
Aaron had made them naked. Aaron is said to have done that to which his actions had led. He had made the calf and proclaimed a festival. The "nakedness" had naturally followed. Unto their shame among their enemies.
Amalekites were no doubt still hovering about the camp; indeed, the tribe probably still held most of the surrounding mountains. They would witness the orgy, and see the indecent and shameful exposure.