Together with the popularization of photography the need of exposure assessment became one basic concern for photographers. Professionals, due to extensive experience plus the development by inspection in the early orthochromatic days could feel at ease guessing speed and apperture. But for week-end photographers that was not so evident and maybe an opportunity to buy more stuff. Measuring, calculating, adjusting was a great deal of the fun for a community of home experts. At the same time, Kodak felt the huge market of consumers that simply would never bother with this things and only wanted the end result no matter how it would look like as long as they could recognize the authenticity of the scene: where and who with no aesthetic or whatsoever considerations.
This exposure meter belongs to the first group. Compared to a simple exposure chart it has no advantages at all to my understanding. But on top you need to evaluate fainting numbers in small holes. When you point the table to the scene you see a row of small holes with transparent to dull numbers inside. Then you must tell which is the last one that you still can read because it is not completely fainted. The difficult part is that you never know if it is recognizable because you looked long enough or not. Next step, saying that you have the last readable number, you must anyway guess light conditions from 0 dark interiors to 14 for sunshine mountains. Then you slide the rule to match you film speed and get the reading on speed and apperture.
For me this is something for people that rely on an instrument just because it is an instrument and because that should be axiomatically better than pure human job. I like very much exposure charts for normal photography. It is a pity that they are no longer in film packaging. Considering that outdoors the light comes from the sun and that it is quite regular along the day in a certain region, afterwards you have only to check for clouds or no clouds, light ones or heavy overcast days and get your right exposure. Simple.