On your YOOtheme WordPress site, some images look sharp on desktop but blurry or soft on mobile.
Why this happens. The original photos uploaded to the site are at low resolution, for example 1000px or 600px wide. Phones with high-density screens (2x or 3x pixel density) need an image much wider than its display width to look sharp. When the source photo is not large enough, the browser stretches it and it goes soft. Photos already uploaded at high resolution look sharp. Only the low-resolution originals are affected.
What you can do. No cache flush or settings change fixes this. Re-upload the source photos at a higher resolution: at least 2048px wide for full-width hero images and at least 1200px wide for smaller tiles.