You are wrong.
The idea is to create a shape, I've no idea why you'd do that, perhaps you'd add the output to your Creative Cloud Library and use it elsewhere...
Anyway what is does is allows you to take a photo of something and then filter the image into dark and light, which it converts to some form of vector image.
So in this case I drew a sketch doodle whilst listening to the keynote at the conference.
I guess I should have drawn a bolder shape, without shading to make useful vector image, but there you go... today is a bit of a departure.
By the way the pencil was a horrible smooth conference pencil, and the paper had no tooth, so it was a bit of a grey skecthing experience anyway.
Then I took a photo, using the app...