blask featured image content

I am developing a Blask website at timyoung.ca
My question involves trying to add images beyond clicking the featured image.
I would like to upload pictures which become the content of (and including) the
featured image, one below the other as in the rope photo in the Blask theme page—
https://blaskdemo.wordpress.com/portfolio/.
Also as in the example of https://miacharro.com, a Blask example website, I would like the image after being clicked, to become larger.
As is, I only see it explained how to upload a featured image.

Thank you