If I wrote you a postcard
I would write
‘wish you were here’
perhaps in capital letters.

WISH YOU WERE HERE
is a banal codification
used when people have nothing to say
but the situation demands a message.
This is known.

But
if I wrote you a postcard
and wrote
‘wish you were here’
perhaps in capital letters
you would see through the context
strip away the convention
and see the message as it was truly meant.
I wish you were here.