I like, "I would extract this to a separate function."
Unless you're asking a question, posing it as a question comes off as passive-aggressive, even if it's not what you intended. A simple declarative statement of, "I would do it this way", is probably best. You don't know why he did it the other way, and he might have had a very good reason (for example, to be sure the subroutine would be inlined).
The best tone to use is one that is neutral and efficient; prefer active voice but avoid imperative mood unless you're 100% sure you're right, in which case it's usually fine.
It probably goes without saying, but you should assume the change was made in good faith. It's possible that the other programmer hasn't seen before what you consider to be good practices; it's also possible that she's great at her job but just made a mistake. It's also possible that you're wrong. So, for this reason, it's always best to be conservative with tone and stay as factual as you can.
Unless you're asking a question, posing it as a question comes off as passive-aggressive, even if it's not what you intended. A simple declarative statement of, "I would do it this way", is probably best. You don't know why he did it the other way, and he might have had a very good reason (for example, to be sure the subroutine would be inlined).
The best tone to use is one that is neutral and efficient; prefer active voice but avoid imperative mood unless you're 100% sure you're right, in which case it's usually fine.
It probably goes without saying, but you should assume the change was made in good faith. It's possible that the other programmer hasn't seen before what you consider to be good practices; it's also possible that she's great at her job but just made a mistake. It's also possible that you're wrong. So, for this reason, it's always best to be conservative with tone and stay as factual as you can.