These are two sample projects for App Inventor 2 "Look" extension.
The "Look" extension could be used for object classification and you could find more information about this extension here: http://appinventor.mit.edu/extensions/
The first sample project (look_demo_for_video.aia) uses video as the data source for objects.
In the second one (look_demo_for_image.aia), stored image from ImagePicker is used as the data source for object classification. You could add camera component to this project and take pictures as data source as well.