Hiding smartshape in tablet and mobile view only

Hi,

Does anyone know if this is possible please?

I have a responsive project in CP9. I have a background image with text boxes over the top, set by the master slide. Some of the images are a bit busy to read the text over the top, and I don't want to fade them out completely (through image edit and reduce the alpha). So, I have put a white smartshape between the image and the text box, and made it 60% opaque. It looks really good but I have now realised that in the mobile and tablet views the images are either missing (by default, no images in mobile view) or in a different position, so the smart shape isn't required in these views, and it looks odd.

Is there a way to hide them in the tablet and breakpoint views? I tried adjusting them so they disappear off the side of the screen but it seems a bit clunky, and maybe there is a better way.

Many thanks.