The meter looks like it has a narrow mirror below the scale graduations. What is that for?
When the needle image in the mirror is at its narrowest, you know you are perpendicular to the needle and therefore you have no parallax error.
If you look at the needle at a slant, the image location on the scale is either above or below the actual reading. That is called parallax. Many high resolution gauges and meters have the mirrored scales and the thin needle like pointers.