The root in retouching is touch; it implies a light if not artistic hand. Breaching that fine line of subtle, the picture quickly becomes fanciful. Careful, judicious retouching can reveal the spirit in the image.
A five-year veil of age on the eyes, lips, skin including wrinkles, blemishes, and blotchiness is lifted in the dissolve in the above video and can be clearly seen in the side by side presentation.
This pose was chosen at random from some studies. Raw, it spoke tired, somewhat resigned. But when retouched, it spoke of a hopeful, determined woman. It is the latter description that correctly applies to the subject Marie.
A picture can do far more than document an instant in time, it can reveal the truth within.