It's nice to have someone to share a "look" with.  To know that there is someone out there who, just by looking into your eyes, knows what you're thinking at any given moment, without having to utter a syllable.  It's nice that they aren't able to read minds or anything, that wouldn't make it special, and besides reading minds would only make it a parlor trick.  To read your mind they wouldn't have to know you at all, would they?  What makes the "look" so special is that they know what you are thinking because they know you...know how your mind works...know what is in your heart.