In this case, the Defendant is acting as his/her own attorney. He/She is entitled to do so. People who act as their own attorney are required to follow the same rules as an attorney would be required to follow. The Judge must be impartial and may not assist either party.
A person acting as his/her own attorney must present evidence through testimony given by witnesses and exhibits, just as an attorney would. Questions or arguments to the Court or Jury, whether by a person acting as his/her own attorney or by an attorney, are not evidence.