It's very hard to correctly select user name while commenting on mobile devices. Even when tap is marked inside the tooltip with username, as the result system decided that I tapped on the link from previous comment and redirects me to profile page. Please look at animation below:
If you look closely you will see that the tap center is located clearly on tooltip and expected obvious behavior is to add name to the comment (light blue circle is the tap position provided from native Android screen recorder tool):
There's a lot of similar situations, when instead of selecting username I can finish with the actions on last posted comment:
- flag it (when flag icon is near to tap area)
- focus on it (when timestamp/link is near to tap area)
And so on.