FAX heart message
Says:
Charlotte ... see you tonight ... I MISS YOU
Who's it from? John doesn't seem to be that much of a romantic where his wife is concerned.
After the fire drill and the awakening in the lounge over "I don't want to leave you". My mind fills in the blanks with the idea they stayed up through the night and planned Bob's foreshadowed "escape from the bar, the hotel, the city, the country"
At dawn Bob looks to his watch and decides to fill a moment with a message to his love. Cut to Charlotte's romm and she is in the shower, not sleeping after being up all night! She's busy. It looks like her suitcase is open across the room to the left of the bed and clothes have been thrown at it. Then the FAX comes with the heart message.
She knows his departure schedule and gets to the lobby to bring his coat. She leaves to spend what few remaining hours she has in Tokyo by exploring. See, he had a ticket to LA confirmed. She might have to wait to get to LA but it could have been that night.
No FAXes ever in the plot from John, so not his mode of communicating. But Bob has had several FAXes and Charlotte even Faxed him a couple of times with directions. The FAX may even be only for inhouse messaging, pointing even more to Bob being the one who would see Charlotte tonight. This idea of inhouse is backed up by the shaving scene phone call informing Bob that a fax has arrived for him at the front desk. If the machines were for external communication, why didn't the fax come straight to his machine? And that fax appears to be directions to the Sushi bar.