Shape hints not working in my case, when I use shape tweens to transform square into rhombi, I add hints to all 4 vertexes but it's still rotate (hint b and d). And without hint, shape tween make it so random. I don't think we should use shape tweens for this type of animation.
This work best for me (though there are still many room to upgrade):
1. Create 6 squares and choose 1 square to be "origin". Origin square should connect to most of other squares. This origin square will have transformation point in exactly center.
2. With each "children" square, set their transformation point to center of their "origin" line.
3. Using Classic tween or Motion tween to transform "origin square" first.
4. Then move children squares so they match with their "origin" line before transform it.
5. Repeat the step till the cube done.
6. After the cube done, we go to the hardest part of adding dot line. We check frame by frame to find out when to add dot line over straight line. Easier said than done but we can do it.
Because free transform tool not allow us to free transform vortexes to make the exact rhombi we want. Setting transformation point make it less hard than do it "free". It's also avoid shape "free" rotate (lol)