On Shinobilegends people can have a clan picture and they can have their picture.
To have a clan picture, you have to be in a clan, and if they have a clan picture, it will show up on your bio.
To have a picture of your own, one that you like, you have to have enough donation points. When you have enough donation points, visit Mission Headquarters, and there you will find the information needed to buy a bio picture and much more.
If you want to put in descriptions of your character or any other things, you can go to Preferences, and then click on Additional Bioinfos.