Mr Beam II has a positioning accuracy of 10 points per millimeter, which corresponds to 250 dpi. In most cases, however, the imaging accuracy of the material is the limiting factor. For example, plywood has an imaging accuracy of max. 100 dpi.
Think about it like this: Mr Beam II can position the laser head with a precision of a tenth of a millimeter, but due to the specific material properties of plywood, the smallest possible combustible point is about 0.25mm in size.