Multi-shadowing is directly related to the selection and layout of LEDs on a board, plus how the emitted light is diffused as part of the total light engine design. In the image below you can see how the Dazor Stretchview magnifier uses 80 wide-angled LEDs densely populated on one board while competing magnifiers use significantly fewer LEDs spaced much further apart.
The lack of LEDs and poor design of most competing magnifiers leads to this multi-shadowing effect. This is a big problem when light is used for close proximity inspection viewing as the multi-shadowing is a major viewing distraction. It can potentially cause defects to be overlooked, reduce productivity and even cause eye fatigue.