Using the Page Curl Block:
First, create 2 images
The teaser image:

And the Open image
Note: it’s a good idea to use SQUARE images

In our example
- the open image is 500 x 500 pixels
- the teaser image is 100 x 100
On the page curl block, select the teaser and open images
Then set the Options

Set the Teaser size to the size of the Teaser Image
and the Open Size to the size of the Open Image

Page Curl Block Tips
Understanding the Page Curl Dimensions
The teaser image and open image have different exposure areas.
Teaser Image:

Open Image:

How to tease by “exposing” the corner of the open image:
To do this nice effect, you have to prepare your teaser image carefully
