Images Added to Pallet Are Not Visible

Maybe I am doing something wrong...?

I am trying to add a .png image, actually two images to my Bracket Pallet. They are left and right curly brackets that I use for combining lyrics.

I am dragging them to the pallet from the score and they add just fine and are usable, but the additions are not visible on the pallet. I’ve tried a few times and sometimes I can get one image to show, but not two.

I am using ctl-shift to drag the image to the pallet and editing is enabled.

The image files are attached.

Thanks in advance for any enlightenment.