In all online forums when someone publish a post mostly they use images for better illustration of the problem or suggestions.
Some highlighting/commenting makes the image more clear.
Currently we need to do the highlighting/commenting part manually in a separate image editor and then need to upload it to forum.
If their is a image editor with basic editing tools, the forum will be more user friendly.
Then a user can upload a image and do the editing part within the image editor.
Further if someone asks a question with a image attached, the person who answer the question can use the same image with his/her modifications in their answers.