For people with a canthal tilt that is either too close to call or just 'average,' it mostly depends on the perspective. In the mirror, you're looking directly and in pictures and selfies you could be tilting your head forwards or backward, furthermore the focal length of the camera lens always slightly distorts faces whether for better or worse. Your best bet to ensure PCT is a good posture with your neck straight and staring "through" things rather than a glassy-eyed 'dissociated' stare when going about your day