In the past I took many, many pictures of models at a professional level ....
1) A video adds around 1/2 stone minimum to a person ... so pictures taken from video are prone to making people look bigger than they may appear in physical life
2) A still picture is all about camera angle, lighting and the general composition ... Any photographer with any skill can make the obese look thinner, the bald look like they have more hair, the thin look obese, the tall look short and vice versa.
Ergo, you cannot trust a picture to be anything ... it is just what it is.
However that does not mean if one sees the subject, be it a person, animal, car or building etc. in physical life, that it will look anything like the picture you have seen.