Gingivitis pictures illustrate moderate to extreme cases of gingivitis. Early gingivitis is less obvious.
These 4 pictures and every picture of this condition that I have seen, is taken of the front side of the mouth. This area is much easier to photograph.
Yet the back side of your teeth is more vulnerable than the front but is difficult to photograph.
In fact, gingivitis occurs most often on the lingual surface (tongue side) of the lower molars. Because access is difficult, these tooth surfaces are hard to clean and very prone to gingivitis and more advanced gum disease.
If the front side of your gums looks good and you still have some of the signs of gingivitis, you may have it on the tongue side where it is almost impossible for you to see.
Have a complete dental exam and don't rely entirely on comparing yourself to these pictures.
Or moderate and generalized...not quite as bad but pretty much everywhere like this photo illustrates.
And this one shows a case of localized mild gingivitis.
Although plaque is the primary cause, there are many contributing factors. Gingivitis while wearing braces happens frequently. It is difficult to brush and floss around orthodontic brackets.