Mobile operating systems can be leveraged for their existing image recognition libraries, e.g.:
- https://catchoom.com/documentation/on-device-image-recognition-sdk/android-on-device-image-recognition-sdk/
- https://github.com/tzutalin/Android-Object-Detection
And many others. Perhaps it would be possible to automatically detect, classify , and reject selfies if there's a need for it.
It could also be used to automatically help provide classifications and descriptions for existing commons images by leveraging thousands of mobile processors.