

Please check you have turned on iCloud Photo Library on your iOS device, so that you can sync the iCloud pictures to all your iDevices smoothly after logging in iCloud account, if it keeps on, you can turn it off and then turn on it again. To delete photos from iCloud, you can either delete them from your synced iPhone or iPad, or turn off photo syncing. Go to Settings on your iPhone and click on

The photos of My Photo Stream will not affect on your other devices.
