Disable pseudo-terminal allocation
This means that the command
verify is run directly on the other side and the standard input/output/error are connected directly to your local terminal.
For commands, there is usually no difference, but it is difference if you want to run interactive scripts (shell). In that point, your output would not be handled by remote terminal, but with your own and the output would not be so pretty. You can try with
ssh -T other_host, where you have terminal access (you don't have on github). On github, it is also one of the resources-saving task, since TTY allocation is "not for free" if you have 31 million users (October 2018).