how do i prove that a collection of contractions does not satisfy the open set condition?

Question

I am studying a fractal that is defined by 4 similarities, similar to the Von Koch curve, and I am trying to verify that it does not satisfy the open set condition.

The fractal is heavily self-intersecting so it seems obvious to me that it does not satisfy the open set condition, but I am struggling to justify it. Are there any standard techniques used to prove the OSC does not hold? Or is the fact that it is heavily self-intersecting enough?