Looks like the images served with this override are low resolution. Wild guess: B2G users are assumed to have expensive data plans, so images are served low-res to save on bandwidth.
Switching back to the iphone UA string ("Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A334 Safari/7534.48.3"), the same images are served in high resolution.
Looks like the images served with this override are low resolution. Wild guess: B2G users are assumed to have expensive data plans, so images are served low-res to save on bandwidth.
Switching back to the iphone UA string ("Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A334 Safari/7534.48.3"), the same images are served in high resolution.