Hi,
Honestly I can't tell exactly what's the issue in your codepen. My best guess is that somehow your CSS is getting in the way (soto speak).
I created a fork of the link I provided yesterday with images and it seems to work as expected:
https://codepen.io/GreenSock/pen/zYLQyzQ
Hopefully this helps. Let us know if you have more questions.
Happy Tweening!