jenny with 1/3rd less than you yet taller by almost 2cm, something must be wrong imo.
[Editor Rob: actually jenny made a comment on the site today, even she knows what I'm an expert in...
The explanation is :
Here, as is what 2cm actually is.
So my head in reality is an inch bigger than jenny's when a photo where we are equal distance is taken And you can can see how her's looks larger in the sterling shot? Because perspective always can play a role in photos, and in this case her being slightly nearer distorts her size in comparison to mine, which is near 1.5 inches behind...
when you are closer you can make yourself slightly taller if the camera isn't above 5ft 8, which it never is in our case. Sometimes it's pretty close mind you, here the camera is about 5ft 4-5.
When taking photos you can eliminate as many uncertainties as possible. Know the footwear difference if any. When standing, try to be on same plane as celebrity or maybe slightly behind if you are unsure of position and stand on flat ground...]