Anyway, the most important thing to remember is that there will never be one idea that everyone likes, the symbol Capn made clearly possesses elements of a form of the tickling fetish many enjoy, this makes it a clear symbol for tickling of sorts and one people could use to express their fetish if they wish.
The neuron tree is also a symbol for tickling, it was designed for that very reason and represents what it was intended for, and if it is ever used, then that is what it will be used for by those who like the design and what it stands for.
The vast difference in opinions means there may never be one symbol, but maybe a few, maybe it depends how specific you want to be about it, I choose the neuron tree because it rather loosely and simply represents our ability to feel sensation whilst being vague enough not tell the world what it is unless people actually know. Rather than including various specific details like, it involves BDSM or feathers specifically etc