The mirror is not necessary, but it is helpful for visualization. Detecting blockages on yourself in a mirror is similar to how you perform distance detection and healing.
Can qi pass through the table to your hand, if your conscious directs it?
Can qi pass through you skin to open blockages inside someone?
Can qi find the source of the blockage even if you directed poorly, but think on the result you wish to occur?
When detecting blockages, it is the clarity of your questions you ask the universe as you scan the body, not where you are standing or which side you are facing.
When detecting, you ask, then you observe and you interpret you're answer.
When healing, you ask and visualize your desired healing, and look with confidence for how you are answered.
Don't worry about the details too much. Do it and learn.
You are perfection.
Iam2 
