Does anyone know what those small ropes attached to the underside of the armrests on their chairs are for?

Looks like they are doing embroidery, which has pretty much fallen out of style. Used to be on all kinds of cloth, clothes, dishtowels, framed samplers, pillowcases--I remember my Grandmother and Great Aunts had all sorts of embroidery around the house, and gave gifts of his and her pillowcases for wedding presents, hankies with initials on them, sachets--I didn't realize how much I missed seeing all that until I saw these young ladies doing their work.

These days, their business would be referred to as a sheltered workshop, like Goodwill Industries, or Lighthouse For The Blind.