Inaccurate results for profile faces

[Mayur28]

Hi,

I'm currently testing the head pose estimation for profile-view faces, however, I am attaining unusual results.
For test purposes, I'm using the 3 following profile view images:

For these 3 images, I get the following results:
Yaw: [70.59546] Pitch: [34.594513] Roll: [33.04599]
Yaw: [81.640686] Pitch: [-8.637505] Roll: [-13.95977]
Yaw: [71.53331] Pitch: [10.675278] Roll: [13.468033]

I am mainly focused on the yaw angles - It is clearly evident that these images contain strictly profile view images, however, neither of the detected yaw angles are close enough to 90 degrees.

If anyone has any ideas as to what might be causing this issue, it would be highly appreciated.

Thanks!