Bohemian Decorated Dish

I think that this dish might have sat originally in a metal holder but it does sit quite evenly without one. It is nicely ruffled and has one ruffle at the rear which is curled over - might this be a thumb holder - well, anyway I pick it up in this manner. Was it purely decorative or did it have a commercial function? The circumference is tinged green and the rest of the body is white glass. When held up to the light there is an opalescent glow. The pontil is roughly ground. The enameled decoration is art nouveau in style. Would it have been made in the first 10 years of the 20th century? I have another one in a similar style [colour-way is cranberry] which I will post soon. Tad over 5 cms high and approx. 21 cms [over 8 inches] across widest point of ruffles.