Open Headshot v2.
Use Image Capture and load a perfectly symmetrical image.
Generate the model.
After generation, activate the Image Matching Tool checkbox.
In the left sidebar, go to Scene → select Preview Camera.
In the right sidebar, under Modify → Attribute → Transform, check the camera position and rotation values.

Observed behavior:
The X Position has a non-zero value.
The Rotation X and Rotation Z have small, non-zero values.

Further test:
7. In Modify → Attribute, use Edit Mesh and apply Make Head Symmetry.
8. Return to the Image Matching Tool.

Result:

The model is now perfectly symmetrical.
The image is perfectly symmetrical.
However, the Image Capture alignment never matches the image.

It appears that the capture process is introducing unintended camera translation/rotation values, which causes misalignment even when both the model and image are perfectly symmetrical.