Hey Markus from Lobe here :) all images and labels stay private to your computer, we don't ever see any of it. We only collect some generic app usage data for telemetry if you opt-in to sharing analytics after installing Lobe.
We do ping online to check if an app update is available! It checks the current app version and our hosted app version to see if we should show a notification that an update is available and a link to our website download.
We do not send any app analytics when it is turned off.
You can read our privacy policy, but more than that, you could use any sort of network traffic visualizer to see that we are not lying we are not in the business of selling data, we are in the business of making machine learning accessible to everyone.
Where is the app-specific privacy policy? the link the footer links to some general "Microsoft privacy policy", which covers all kinds of things and if it has anything specific to this app, it's impossible to find.