Test: Retina images

320×320px, quality 80, 50,468 bytes

640×640px, quality 60, 99,023 bytes

640×640px, quality 40, 59,739 bytes

640×640px, quality 20, 42,626 bytes

320×320px, quality 80, 48,447 bytes

640×640px, quality 60, 86,214 bytes

640×640px, quality 40, 52,014 bytes

640×640px, quality 20, 37,655 bytes