On the Dashboard, there is a button at the top right hand corner that says "Settings". Tap on that and it will bring you to this page:
Go to Settings> There is an option to "Use smaller images". If this is selected then the Mobile Sales App will use smaller, compressed image files from your QuickBooks Commerce account instead of the full quality, original sized images.
This will reduce the initial sync time and also help with overall app performance, especially on older devices. If your app crashes or slows down on pages with a lot of images, enabling this setting should fix the issues.