It's amusing the way that Ibrahim Guvendikler has taken the simple concept of a wedge and imagined it into something with far more character. The Nuclear Door Holder acts as both a door stopper and a "keep out" sign, sticking to a more dramatic tactic than usual for a comical effect.
The general chock shape was maintained in order for this nerdy knickknack to function but its form was manipulated into the body of a squeezed plastic tube. Rendered without a cap, the container was made to seemingly squirt out a snake-like line of neon green or blue paste. The suggestion here is that this is highly poisonous and radioactive material.
A black and yellow warning label further clarifies the supposed contents of the Nuclear Door Holder as a playful way to say "stay away," even when the door is ajar.