I think the most important "feature" is that the UX needs to be stupid-easy to grok. Before I would ever consider using something more complicated than still images on a simple web page (which is what most of us have now), I would need to be 100% confident that I could hand the device to a potential employer at a trade show and they could navigate and use it without me having to explain a single thing to them.
Ultimately we aren't your customer, the person reviewing portfolios at trade shows is. They might be an art director who has two decades of experience using Maya, or they might be a recruiter who spends most of her day in IE and Outlook. Both people need to be be able to just jump in and look at art, unfettered by UI. So put yourself in the shoes of that person. What are the things they might want to do?
- Arc/rotate, pan, and zoom
- See it with all textures and shaders and final lighting
- See it in gray mode with just normal and specular maps
- See it in flat lit mode
- See the wireframe
- See texture flats
- See information like triangle count and texture sizes, etc
- Quickly swipe to the next item in the portfolio