If Grocery King app on your device has some images missing compared to other devices in the sync group you could try the following to get back in sync :
- Open Grocery King app on the device that has all the images.
- Tap on the main menu button (hamburger shaped) on the top left corner of the Shopping Lists screen. Now tap on the Account Settings button on the top. Go down to the bottom of the Account Settings screen and tap on the menu button next to "Advanced Sync Settings" row.
- Tap on "Send all images on device to cloud"
- This should push all images on the device to the cloud and transfer those images to all other devices in the sync group.
- Check on your other device if the images have transferred. If they haven't yet made it then go to "Account Settings" and tap on the "Sync Now" button at the bottom.
If this still doesn't work then open Account settings on the device that doesn't have images and tap "Advanced Sync Settings" -> "Fetch all images on cloud to device"