HI,
FindFaces just finds (anything that looks like) faces (mainly eyes).
It doesn't try to recognise individual faces.
confidence is a measure of how sure it is that it has actually found a face.
eyedistance seems to be the distance between the eyes,
and midpoint is where it thinks the middle of the face is,
I presume pose indicates whether this is full-face or three-quarters or profile etc.
See Sample (touch rocket icon in top-right) Camera Faces - Find faces in the image
Regards, ah