This will simulate the measurement of 'transmission' or more accurately put, the color integral of each color channel from the side at angles 0 to 360 degrees, generate a sinogram for each channel with the y axis as the angle and the x axis as the line integral measurement at that angle, before finally reconstructing the original image from those measurements. In real world applications, this would be measuring transmission through an object/person from multiple angles in order to analyze the internal structures of said object/person.

If that sounds confusing then think about it this way, if you could see through an object and only imaged it/viewed it from a single angle, none of the three dimensional information is captured/seen, it is only when you go ahead and rotate that object, viewing from many angles, do you see/capture the internal three dimensional features.