I noticed that the same bug marked as fixed (status-complete) in this question still exists when using a mobile device:
When I'm not logged-in, and click the "Show N more comments" link, then:
- the hidden coments are show
- the "Show N more comments" link stays visible
- when I click the link again, I get a small yellow popup with the message "Commenting requires an account with 50 reputation"
I reproduced this bug on an android 4.3 device with both the latest Chrome and the standard android browser.