I use instagram almost entirely to showcase my photography:https://www.instagram.com/imjustjk/. It's certainly not a perfect platform but it's good enough (and better than most). It's a mobile first platform that's simple, intuitive, and has huge adoption. It also has great loading speed for the amount of content and even the quality of images. I'm not sure what you expect on a mobile app? Do you want to be able to load full 42 megapixels images of mine on your phone?
Well the photos my brother takes are studio based - he's getting into product photography, so the shrunken, low quality pictures served by Instagram are just frustrating - I want to see something where I can zoom in to enjoy looking at the details, rather than something that's a quarter of my phone screen at native resolution.
