I do not know how to answer your question... sorry.
This is what I have done...
At Snapagogo site in my album where my images are, I first choose the image I want the links to by clicking on the image. That brings up the photo itself. Under the image on the left there is some text that says "Embed Codes, Links & URLS". I click on that text and it brings up a list of choices (links) to choose from. I pick the HTML link from the Medium image (linked) box and copy that. Then I paste that link in the body of my post and what you see is what you see here below in the actual post.
Hopefully this will get you going.
Medium image (linked) HTML
Uploaded at Snapagogo.com
Here is an experiment...
This is from the Direct Links choices, Medium URL...
Maybe this is what you are looking for????