Inaccuracy of picture and actual view

Hello,
the picture tells what my problem is. The black lines are drawn in the hololens with unity and GL right in the center:

GL.PushMatrix();
lineMaterial.SetPass(0);
GL.LoadOrtho();
GL.Begin(GL.LINES);
GL.Color(Color.blue);
GL.Vertex3(0, 0.5f, 0);
GL.Vertex3(1f, 0.5f, 0);
GL.Vertex3(0.5f, 0, 0);
GL.Vertex3(0.5f, 1f, 0);
GL.End();
GL.PopMatrix();

here is the picture, stretched to 1920 x 1200. The center of the black lines is 937 x 572 and the red lines 960 x 600.

I usually would assume, that they match perfectly, and that is what I want. How can I correct this with unity?
Thank you very much.