On the comments page, choosing the option 'with XX context lines' displays XX lines starting at the beginning of the diff section.
However, if the diff section itself is longer than XX lines, you won't even see the whole diff there. In these cases, I have to switch back to the code view, which is inconvenient.
I would therefore suggest that 'with XX context lines' means:
- Show XX lines before the diff start line.
- Show XX lines after the diff end line (not start line, as seems to be the case now).