I just noticed the same thing (1 recommendation out of 250+ listings).

I clicked the link and to the right of the title is a purple 'i' - click the + sign next to that to view eBay's recommendation. Mine just said to add the material selected in the item specifics to the title, so I suspect most of the recommendations would be along similar lines. (eg if you have cotton in the specifics but not the title - a lot of item specifics are keyword-searchable anyway, so it won't necessarily make a difference).