When is "dress" a mass noun?

Question

I find the singular/uncountable usage of "dress" strange in this sentence.

Expansive skirts on fashionable dress of the period proved the perfect blank canvas to showcase chintzes lush with pomegranates and lotus flowers à la Indiennes. (source)

According to Macmillan Dictionary, "dress" is a mass noun only with reference to "the clothes that are typical of a particular place, time in history, or occasion", such as "military dress." This is also supported by Cambridge Dictionary, which has more examples of "dress" as a mass noun. This sentence apparently does not fit this usage. I thought it should be

Expansive skirts on fashionable dresses of the period proved the perfect blank canvas to showcase chintzes lush with pomegranates and lotus flowers à la Indiennes.

Is the original text mistaken?

Answer 1

Your suggestion and the original are both possible. They would simply have different meanings.

The cut of skirts of fashionable dress (i.e. wear, clothing) of the period tended to be well above the knee.

The sleeves of fashionable dresses of the period tended to extend to the wrist.

When dress means "typical clothing" in the first example, it might include a woman's business suit with a short skirt, say, or a casual skirt and blouse ensemble, that is, a number of different kinds of outfits all of which could fall under the rubric "the dress of the period considered 'fashionable' or 'with the times' ".