My first thought as well: Those would be covered in flies, ants, and/or other bugs if I tried it around here (which is not Mexico). It makes me wonder if this photo is taken some place that doesn’t really have much in the way of bugs, as hard as that is to imagine, or if they go to great lengths to kill all the pests in the area to prevent them from taking over the tomato yield.
I dry them in a food dehydrator or in the oven. There’s no way I could leave them out, exposed like this in my part of the world.