On small screens like that, higher resolution doesn't really make that much big difference. You can try out an iPhone 5s and a Galaxy S4 and make them watch the same movie. You wouldn't really see any pixel quality difference despite the resolution difference, rather, the color saturation is the variable. To answer your question, it wouldn't be worse at all. Besides, the pixel density of Nvidia Shield is 297 pixels per inch. And as Steve Jobs once said, anything higher than 300 pixels per inch, would be like a fine print as we will not see any individual pixels anymore. So both of them would look the same on a human eye.
*Color saturation, in-game graphics, and anti-aliasing might differ due to different Screen hardware and Graphics Processor.