Layout of a photo in Home page (mobile and screen)

[LAC1993]

hello, 

my website www.lateliercommerce.com 

password: Lac1234

in the website i am using theme modular. 

My problem is on the main page.

I have a SLIDE SHOW resource that allows you to put one image that will appear on the mobile and one image that will appear on the computer.

The problem is with the image sizes, when I change one of them it changes the other.

both photos is now in "full screen" height 

i want to change the photo is the main page to be "image height" not full screen - this is better for me 

but when I change it above it immediately change the photo on the mobile although I keep the mobile option on "full screen" 

please assist, i try to change resolution and more but it doesn't work. 

Thanks