...hmmmmm, hate to disagree; but after endless research I have found the HOODMAN AVIATOR series to be THE BEST sunshade on the market for seeing a monitor screen in bright sunlight:
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...the problem with all open-sided shades is they do not eliminate the reflections from the screen - only when ALL sides are blacked out and your face blocks the top opening will you see a glare-free screen with zero refections - it's just simple physics. (...further endorsement: if you see the NFL referees reviewing a play on the field at a video booth, they will be using a HOODMAN product.)
...some other reflection-fighting tips:
• I've placed a slightly matte screen protector on my iPad screen to dull the sharpness of reflections - way less distracting than sharp reflections.
• I always try to wear black shirts/jackets/hats/ninja-face-wrap

and keep my background as dark as possible to reduce any bright reflections (...find an operating position that has shade at your back)
• if I am in a situation that's appropriate for sitting, I've found a very effective fold-up chair by Renneto that has a fantastic awning system to block sun from many directions, yet still gives you a clear shot to track your drone with your eyes:
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