I am guessing you are correct. That 5k image is probably going to be the 5k medal. The other medals are the same every year, but with different colors correct? Ive only done them two years, but my 10k, half and glass slipper medals are almost identical from 2014 and 2015. Most people think they are identical, I have to show how they are different. But the the differences are medal color, gold vs. silver and ribbon color. Also, on the 10k medal there is an image of cinderella's carriage above the "10k" vs a snowflake for 2015. I'm guessing 2016 will have a seashell there.
I'm guessing those exact images will be our t-shirts, because those images look a lot like my other 7 t-shirts