Seems to me the wording is wrong on the second option. It says “use value from this field on this sheet.” Then it says “Update To”. Then it says “this field on sheet …” Should it just say “update”? Saying “update to” makes it seems that the current sheet (one on the left) is updated to match one on the right rather than the reverse.
I have asked our developers to check this wording issue on this feature and will notify you when we have new information about it.