ThemeForest - 3xistence - Responsive Tumblr Theme | 21,1 MB
This theme was designed especially to showcase your beautiful pictures in high resolution! Yes, it works also on mobile devices, because all pictures uploaded by you with traditional way (i.e.: through Photo posts) are automatically swapped for their smaller versions to fit on mobile devices.
DEMO:
http://themeforest.net/item/3xistence-responsive-tumblr-theme/2974548