Hi,

We don't recommend you to show the text on mobile devices. Please note the screens of the mobile devices are not large enough to display much information. So if you display it the design will be messed.

If you still want to display it, use the CSS code below: 

@media screen and (max-width: 600px){
   #wpdcom .wpd-social-login .wpd-connect-with {
      display: block !important;
   }
}

Put the code in the Top Admin Bar > Customize > Additional CSS > "Additional CSS" textarea, save it, delete all caches and check again.

Also, please try on incognito mode if you're checking on mobile devices. Because mobile browsers have a hard cache, you'll not be able to see the change immediately.