I can't measure it because I'm on holiday, but I think it's right. The vacuum cleaner has a relatively thick round cable. Another model I know has a half as thick, longer cable. A thick cable takes up more space on the reel.
This is due to the suction power. The Miele Complete C2 Black Powerline has a suction power of 890 W. The Miele Complete C2 White Ecoline SFRG1 800 W (power consumption 1600 W).