Hg Pull vs. Update to branch tip

Question

Using TortoiseHg Synchronize, clicking "Pull" pulls down the 2nd most recent revision.

At the bottom of the Synchronize interface is a button, "Update to branch tip." Clicking this button pulls down the most recent revision.

What is happening here?

Answer 1

Command line hg tells this:

$ hg help pull

...

Pull changes from a remote repository to a local one.

...

-R is specified). By default, this does not update the copy of the
project in the working directory.

vs.

$ hg help up

...

Update the repository's working directory to the specified revision, or the tip of the current branch if none is specified.