You can now reference or comment on multiple lines in a pull request diff view.
To reference multiple lines click on a line number in the diff view, hold shift, and click on a second line number. The URL of the page will update and can be shared with fellow contributors.
To leave a comment referencing multiple lines click and hold to the right of a line number, drag, and then release the mouse when you’ve reached the desired line.
If you have any feedback about this feature, we’d love to hear from you: https://support.github.com/contact/feedback