How do I change a user created Slot Widget Image?

I have created a Widget to place within my Skill Tree widget, these widgets are simply to be Buttons with an Image over them. Their functionality works (in that I can click it in the skill tree to “unlock” that skill) however I am unable to change the image. As you can see below the “Slot Widgets” consist of a Button → Size Box → Image. These Images are exposed and editable.

However, when I try to modify the image to a stock Fireball I found online, it will not take. The only way to get the image to actually take to the button is to modify the default Slot image, which then changes all of the buttons to that same image.

How do I go about changing the image variable (Texture 2D) for each individual button?

Solved - While talking with Voletek during his stream we came to the conclusion that I hadn’t actually bound the image’s brush to anything. So while I had a variable “Action Image” it wasn’t bound to the Image Brush itself, resulting in no visible change.