The phrase "streamlined silhouette" refers to a sleek and smooth outline of a person or object that appears to flow effortlessly. It emphasizes a clean and modern look without any unnecessary details or bulkiness. Full definition
To avoid costume - y vibes, wear them with streamlined silhouettes in the same shades, like black cropped skinny jeans and a crisp white button - front blouse. (instyle.com)
But if you'd like to feel taller then a few extra tips will help you to create a more streamlined silhouette, consequently looking taller and slimmer. (style-yourself-confident.com)
The best way to go about this is to avoid fabrics that are super bulky, and go for streamlined silhouettes instead. (fashionandstylepolice.com)