You may decline (Cancel) or accept (Update). I recommend to accept always, because any new version is better and more stable than the old one. When you press Update button, script downloads file bonyface.zip - an archive with the new version, puts it into internal folder BonyFace\updates, extracts files to main BonyFace folder, replacing old files. After successful replace folder updates should be empty. Of course you don't need to check that every time, just take a tip - if update process didn't finish with success somehow then you may move files from folder BonyFace\updates to main BonyFace folder manually.