Buenos días Dennis

You're right to notice the apparent inconsistency between the plural "los modelos" and the singular "un albornoz" in Spanish. However, this usage is actually quite common when referring to a situation where each person in a group performs an action individually with their own item.

In your example, "Los modelos se pusieron un albornoz", the sentence suggests that each model put on a bathrobe (presumably their own), but it’s expressed in a way that focuses on the action and the item rather than the number of items. This construction is used to emphasize the type of item or action rather than the quantity.

If it were essential to highlight that each model had their own bathrobe, the sentence might be rephrased as "Cada uno de los modelos se puso un albornoz" (Each of the models put on a bathrobe). But in everyday language, the original sentence is perfectly natural and understood to mean that each person engaged in the same action independently.

Saludos

Silvia