Its not testing the speed to your phone..
You should run one of these from your phone's browser (or use their apps)
TestMy.netAccurately test your Internet connection speed with this powerful broadband speed test. Improve your bandwidth speed with the truth.
https://testmy.net[testmy.net]
and speedtest.net (although not the best)
However... the only way to truly test your speed is to use something like 'iperf' or other network tools (not easy for most people).