Level AAA − WCAG 2.0 Success Criterion 2.1.3 − Keyboard (No Exception)
With no exception, all content must be operable from a keyboard.
Before Rectification
In this situation the system only allows a user to use his/her "mouse" to create the drawing. This is not accessible to persons with restriction in body movement who cannot use a mouse.
After Rectification
In this situation the system allowes the user to create a picture using the keyboard and also provides instructions on how to achieve this. This is helpful for persons with restriction in body movement.
WCAG 2.0 Reference:
http://www.w3.org/TR/UNDERSTANDING-WCAG20/keyboard-operation-all-funcs.html