–•– (Dash Dot Dash) app displays pictures on home screen (or widget area) widgets. It keeps pictures located on your local home screen widgets only on your device.
If you decide to display your picture on your friend's widget, it will be uploaded to your iCloud account and shared with your friend's iCloud account.
If you decide to display your friend's picture on your widget, the picture will be downloaded from a shared area of your friend's iCloud account.