What determines the various shapes that show on the Tangle Explorer?

Question

The Tangle explorer is currently displaying an "IC".

Is this a secret message?

What determines the various shapes that show on the Tangle Explorer?

Here is another example, while The Coordinator was turned off:

Answer 1

The tangle visualizer you took the screenshot from uses a simple physics/force engine to determine the place of transactions.

• If the "reduce movement" box is not checked, new transactions appear at one fixed point in the center
• If the "reduce movement" box is checked, new transactions appear at a random distance from the center between their trunk/branch transactions

Afterwards, the force direction based layout is used by the VivaGraph library to move the points around. This algorithm will drag transactions connected to the new transaction slightly outwards, while dragging the new transaction back to the part of the tangle where they are connected to. At the same time, not connected transactions will repel slightly, causing the side tangle(s) to separate from the main one.

So transactions which are referenced later or more often are prone to be dragged more (to the center if "reduce movement" is not checked).

There is also a Wikipedia page on Force-directed graph drawing in case you are interested in the math behind it.

Creating "secret messages" like this might be possible, however it is likely infeasible, as the tangle visualisation looks different depending on how long you have been watching it (and therefore how many old transactions are there that affect the physics), so even while theoretically possible, you cannot be sure that anyone/everyone will actually see your secret message.

[If you are curious, for me the visualisation right now looks like a "91", with the 1 being the side tangle and 9 being the main tangle]

Also there are other actors whose might disturb your picture, especially since the algorithm is a chaotic one, i. e. small input variation may result in great output variation.