[Steven Zahm]

@ Kevin

Once installed, there is nothing to configure or enable, it works in the background. It is not immediate, the processing happens in the background because face detection via PHP is intensive and time consuming. While it is processing the original image will continue to be displayed. If at this point it is still not working, the face detection is far from perfect, so it might not be able to find the face. Though, those two images it appears they should not present an issue. With that said, I did download both images from your site and tested them on my dev site, the face detect did work as expected.