The first sketch just displays 3 dimensional scatter plots, histogramms and some sort of what in statistics is called standard deviation.
On the gound plan, the sample images are displayed.
The black point clouds represent every pixel at their position in the color cube. The red value is defining the x-coordinate, green and blue y and z respectively.
The bounding box around that point cloud shows the extent with the stroke color representing its longest side.
Along the edges of the pictures, the corresponding histograms are being displayed.
The height of rectangle standing upright at the back of the picture represents the standard deviation. A high value results in a strong contrast.
The black diagonal is the gray line going from black (0,0,0) to white (255,255,255).