My original incorrect solution came about from over-analyzing the word "rose"...
I took it to be a play on the homonym "rows". The title is designed to make you think of the flower, but it's actually about rows of spots on the dice.
If you count up the number of rows of three dots, you get half of the correct answer. (One row of pips on a 3, two crossed rows on a 5.) It works unless there's a 6, which should be two parallel rows of pips, but that throws off the count.
Now, once you get this solution in your head, it's really hard to shake it and go back to a visual interpretation of the game's title. This is why it took me so bloody long to solve the thing. (That's my story, anyhow!)