create a front and backpage with a 2D plane

Hey everyone,

I am currently working in After Effects 2020 and I want to create a 3d book.

So far, everything works out as intended, however I ran into the following issue:

 As you can see, I created the single pages with a new composition of a 2d plane. When I animate them to turn the page, it looks like this:

The thing is, that I would like to have a front and a back page, not the same image flipped over on the back. 

So my question is, how do I achieve that? Do I have to use a very flat 3d plane to project an image on the back, or can I do this only by using the 2d planes I have right now?

Thanks in advance!

All the best,

Adrian