That is not a good analogy. The reason knowck-off luxury purses get confiscated is because they are using the luxury brands' marks. The fashion industry is actually the perfect example of not being able to sue for 'look and feel'. There are very few trendsetting concepts or designs in fashion and 99% percent of the products sold are knock offs of some other product. The fact that you can't sue to protect a design is why there is tons of innovation and creativity in fashion.