Here’s a very quick’n’dirty version of the Scratch project:
Code: https://github.com/britzl/publicexamples/tree/master/examples/greeting_card
HTML: http://britzl.github.io/publicexamples/greeting_card/index.html
I decided to build it using a GUI scene since there was text involved. I use gui.play_flipbook() to change animation on the different nodes. The whole thing is 47 commented lines of code so it should be fairly easy to understand how it all works.