Adobe Spark Post - How do you resize a photo?

Hi

So I have been stumbling along with this issue.  I add a photo in SPARK POST and it then fills the entire page as a background.  I tap on it and I cannot figure out how to make it smaller.  At first I thought it might have to be a PNG and then tried changing images for that and still couldn't make it work.  I am getting frustrated.  Any help here would be most welcome.  I thought maybe it was the order of the photo but that didn't make a change and their is no resize in the menu that I can see either.  At the same time, when I play with some of the templates I see that this is possible.

Thanks

Brant