Issue with Layer Slider Images

I’m using the layer slider I’m trying to use a logo (.png with transparent background) as one of the layers. I would like the logo to have a black box around the image just like the text in the sample demo. The black box does show up in the preview in the layer slider setup area, however, on the live site all I see is the logo and the shadow generated by the CSS.

What setting should I adjust to get the box to show up on the live site and how why might the preview show the box and not the slider on the actual homepage?

Thanks for the help!

-Chris