Would a person's body type look different in pictures than what it really looks like in real life?

The camera has no brain to compensate for what it may see and how it sees it, like your eyes do. And your eyes see in stereo while the camera lens does not.
I can take a picture of you and make it look as though your head is really big and your body gets skinnier as the picture goes down to your feet. If the camera is held at the same level as a woman’s chest, it will appear bigger, and the lower I hold the camera the fatter the subject will appear.
I once took a picture of my brother and mother. My brother had his hands out in front of his face at arms length holding his knee. If I had taken the picture like that his hands would have looked huge in comparison to his head.
The closer the subject is to the lens will cause the subject to be distorted from real life, but more normal the further away the subject is from the lens. Provided, of course, that the camera lens is of correct focal length and not a wide angle or fish eye lens.

Yes, in addition to what @kritiper wrote about where the camera is, the lenses cameras use are not the same as a pair of human eyes, and there are different kinds of lenses, and with digital cameras there’s a computer processing the light and modifying it. The sensitivity to light levels, light/dark contrast, and colors is different. Lighting can also makes big differences.

Another huge difference between pictures and seeing someone in real life is that a photo is still and 2D, and actual humans move all the time and are 3D. Many instants, when frozen in a photo, look rather weird and unlike what a person seems like when watched in person.

Also, different humans see differently, with different types of color blindness and with different viewing defects. Many people have vision defects they are not aware of, because they are used to their own vision and changes tend to be gradual.

You can test these things for yourself by comparing what people look like in real life to photos of them.

However, attention and mental expectations also play a role. Many people are used to looking at themselves, and to relating to looking at people and comparing them to ideas. For example, this is how you can have people who are starving themselves but think they look fat and overweight.

A lens like a fish eye will distort an image.
If you are using a standard lens that captures things as they are with no purposeful distortion, you are still only capturing an image of something in that split second, from whatever angle they are at and whatever light is there.
In that split second though, the subject could blink , be speaking or posing or be in an awkward position that could look crazy when captured in that split second.

The old adage “the camera adds twenty pounds” is based on actual perception from television camera lenses that tend to be wider angled so that they stay in focus.

There are a lot of ways that a mode can pose, and placement of the camera, to accentuate length and slenderness.

@Zaku To be more specific, the reason I ask this, is because it made me confused and at the same time curious, the fact that my brother was talking to me about an attractive girl he knows from college, stating that she has, what he would say a “sexy body“ or “ curvy figure” so he asked me what I thought of her physically speaking, so he showed me pictures of her in different angles, and I just did not see a curvy body in the pictures, what I saw was more like a straight or rectangle body type.

So it got me confused and thinking on why I see these pictures any different than him, because he made a big emphasis in her having a curvy body, I just personally did not see it, and trust me, I have studied body shapes before in a college class, but maybe since he knows her in person she looks different from the pictures that he showed me.

That case sounds to me like it would involve both the camera aspects and your brother has seen the person moving in person and she got his attention so he has a mental model of her and when he sees a picture of her his brain recognizes it and reacts not just based on the photo.

People also tend to relate to people they are attracted to or have ideas about as if they were objectively more beautiful.

Also, a lot of beauty comes from how the person behaves and how they are being, which can make a dramatic difference in how attractive they seem in person, but only part of that will show up, and only in certain photographs. Which is why beauty photography is a serious professional skill that takes a lot of work, great equipment, thousands of shots most of which are thrown away, Photoshop work, etc.