How to fix face of a girl by using photoshop

1. Use liquidify to fix the shape of the face
2. Use Alt + click to select a color and paint tool to cover some unwanted colors. Use dodge tool or burn tool to change the exposure of the touched areas.
3. Use the technique in this video: https://www.youtube.com/watch?v=Qw5dUVTmzro. To summarize: separate low frequency and high frequency.
To get low frequency: copy the layer and use Gaussian blur
To get high frequency: copy the layer | Image | Apply Image | select the low frequency layer, blending: substract, scale 2, offset 128. Then change the blending mode to Linear Light for the high frequency layer.
Done.

Understand Ellipsoid, Geoid, NAVD 88, WGS 84 etc, oh my

Very related reading: https://www.groundcontrolpoints.com/

How do geoids relate to datums?
Undulation values represent the distance along the ellipsoidal normal from the ellipsoid to the geoid.  As such, each geoid is referenced to a specific ellipsoid and datum.  For example, the
Geoid96/Geoid99/Geoid03 undulations are all relative to NAD83, while EGM96 is relative to WGS84.  It is important that the correct datum be selected when using a geoid for MSL height input or output since the horizontal position will determine the undulation value applied.  Where
the difference between datums is small, such as WGS84 and ITRF, the error will be negligible given the grid spacing of the geoid, but for other datums, such as NAD27 and NAD83, the differences are too large to ignore.


https://kknews.cc/world/lknzeo2.html
https://gisgeography.com/vertical-datum/
http://www.lidarmag.com/PDF/LiDARNewsMagazine_Kessler-ImportanceOfDatumsInMapping_Vol4No5.pdf