While looking at what I am pointing out, keep in mind that you are looking at a visual representation of the workings of a basic "process" in all living things and applies to the "behind the scenes" workings of ALL creative processes as well.
Pointing out these elements will help you understand this process that is called change so as to avoid the negative daliances that an unclear path can present. Negative daliances add up to suffering.

This "The Last Supper" is being used to show two other communicative elements.."groups of three" and the "Reflection".
The blue cursors point to the central figures or element in each group of three. There are six "groups of three" being pointed out by the blue cursor. Those are the primary "groups of three" though more exist in the painting.
"Groups of three" are elements that share a closer relationship to one another than to the rest of the elements in the total picture. The placement of a group of three in a visual composition tells a story of balance.
I could tell you the story this composition is relating but that would be to take the fun out of it for you and beside ya wouldn't believe me :-)
Now there is a reflective communicative element as well and in order to observe this element it must be understood that one must look past things like history, reputation,name etc and focus only on what is to be seen.
For instance, find the two green cursors at opposite ends of the table and you will see that these two figures appear to be very similar in essence and appearance.
Now look at the yellow cursors and again the two men essentially the same.
Next is the red cursor and the same thing.
And the last of these "look a-likes" is the orange cursored two women.
Now, looking at the positions of all "look a-likes" on each side of the central figure you should be able to see that, visually the "Two groups of three" to the left of the central figure is a "reflective opposite" of the "Two groups of three" to the right of the central figure. You will notice that the central figures (blue cursor) on opposite sides of the Central figure are opposite in apparent gender thus reinforcing the portrayal of reflective opposite.
There is more will post.
Lalepop'