The actionscript now calls for the same piece given different numbers to distinguish them. You can modify the piece symbol (add a picture, change the color... or whatever) but presently that would just reproduce 15 similar new pieces with different numbers.
To achieve your goal, you would have to design 15 different pieces (or maybe 1 picture cut up in 15 pieces) and change the actionscript accordingly!
Challenging!
When are you starting?
;-)