Ouch, Miki!!!
I would feel very uncomfortable "interpreting" someone else's photograph. Keep in mind... it is a piece of art, in it's own right.
If you copy someone else's work in anything other that a 'study' for your personal use... I feel that you are treading on very thin ice.
I use photos also... I normally take them myself or even if they are from a friend I feel obligated to pay a % of sale price of my piece.
Just a thought.
Linda