Expand Photosize with size of screen

I am using the Photo Album Plus and have implemented a couple of photo slideshows with maximun slideshow sizes. My customer is complaining that on a big apple screen the photos look too small and wants them to dynamically expand with the size of the screen. I have googled this but cannot find anything that would solve this issue – although she says that she has seen this on other sites (I am still waiting for an example). Does anyone know either a solution to this or a photo album plug in that supports this?

Thanks Guys!

The site is https://www.hairandmakeup.nl/