Schools and school districts that use Edsby generally choose not to allow students to manage their own profile pictures as a matter of policy. Some import official school pictures as students’ Edsby picture. Some don’t allow any pictures at all and only use a default icon for every student.
If your school or district has imported a picture of you that you’d really like to change, speak to the office at your school and they may be able to help you. However, there is no guarantee.