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.
Learn more about pull request comments
If you have any feedback about this feature, we’d love to hear from you: https://support.github.com/contact/feedback