Browser loading content from Twitter in admin area?

I have noticed that when I am in my Dashboard and switching from main Dashboard to for example plugins, Twitter seems to be loading something.

As I am located in China where Twitter is blocked, it always takes forever for my browser to realise that Twitter cannot be loaded, and thus before the page(s) finish loading.

This screenshot is for going to the plugins page, but it happens everywhere in the Dashboard.

Is this normal? And can it be blocked/removed/undone?

• What happens when you try it with all your plugins disabled?

• What happens when you try is with the default WP theme?

• What happens when you try it with a different browser that has no browser extensions or add-ins installed?

• What happens when you set twitter.com -> 127.0.0.1 as suggested?