My photos have a white cloud in the bottom corn...

Cloud in bottom of pictures and won’t send

The cloud icon means the photos have not yet downloaded (synced) from iCloud Photo Library. Tapping on one of these photos, forces it to the top of the line, so it will open at full resolution.

If you have a large library, sync may easily take many days. Leave the devices ce charging and connected to Wi-Gi overnight for a few days.