They think they are ugly maybe?? LOL

A) They're involved with someone already, but are looking to fuck around on the side discreetly.

b) They're not highly-motivated to build their profile and attract attention.

c) They're fuck-ugly.

Yes I realize we are going to change over the years, but over the years I have known a few woman that are slender and have a high metabolism usually they signed the matter how old are you they get, and big women usually stay big or lose weight and gain it back....

Because we want to find someone who would love a good surprise !!!!

Pure speculation (mostly likely not the case) but your question does bring to mind a rather "funny?" observation I made many years ago. The sister of a co-worker showed up at work and was very happy. Her romantic pen-pal was flying into town to see her the very next day. She had a stack of photos showing the man she was expecting and eagerly shared them with us. About a dozen images showed a tall strapping hunk of a man with flowing blond hair wearing only (in once case) a tiny and tight swimsuit with his surf board posed before crashing wages. All but one of the images was similar clearly demonstrating youth and physical fitness. One image however, (not of the quality of the others) showed a group of people at what appeared to be a Halloween party. She noted she couldn't tell which one in the group was the man she was eagerly awaiting. I instantly recognized her love interest as the chubby, bald, and notably not youthful or healthy, shortest man standing and smiling in the center of the group. I pointed him out and noted, unlike all the other men in the photo, this man was not wearing make-up, no bald wig etc. I then explained all the other photos were a decade or more old (probably from his High School years) and father time did not treat him well. She could not believe my observation but the following day, her sister confirmed my observation. In contrast to what he and her potential romantic fling had planned, he flew back home (alone) the next day.

I have no idea. Ask them!

Can think of a few reasons just for starters.

1. They are only interested in people who like who they are not just what they look like.
2. Unlike some who are forever taking photos of themselves they do not have a current picture and do not wish to misrepresent their appearance.
3. They have an ex out there who they don't want to be found by.
4. They look too good and don't want a stampede.
5. They are not very photogenic.

And that's just for starters.

My first thought is they're married.

Some people prefer to keep their photos private. Maybe when you meet somebody who intrigues you through their words, you can ask for a picture. This has been discussed here ad nauseam -- even just two days ago,

They don't want to date anyone?