What is causing these images to be greyed out?

[oliviawaite]

Dawn theme used. Not sure what is causing the issue as shown in the mobile version screenshot below. I had added coding to the custom CSS of the Multirow: h2 {
font-size: 25px;
}

Is this causing the images to be greyed out? I would test this out myself but I don't have an iPhone 12 but my client does. If there's another fix to resolve this and make the images compatible, please let me know! Otherwise, I don't have issues on my iPhone 15. 

website: nowisensors.com