I dunno. You have to have a standard. A standard is used as an example by which all others are compared. It works with gold, calibration of instruments, and is even used to imprison people. Whether they occupied the same space or nearby is meaningless to me. YMMV.
She did go to meet the King of Spain in that outfit. To be fair, the Queen was dressed casually. The Princess was dressed smartly and looked fabulous.