Chinese is of course not a pictographic language it's an alphabet like western alphabets.

We kind of have pictograms in Unicode already like ☢️ or ⚠️ or ⚡ which are universal even though they don't really represent physical objects.

The radiation icon particular doesn't really make any kind of logical sense, radiation is in non-visual threat so there's no reason it should look like that, over anything else, and yet everyone knows that's what the symbol means. It's not a picture of something, it's the picture of a concept.

Equally there's no real reason that warning should be a triangle and electricity definitely doesn't look like that. Again though we kind of don't even think about it we just know what the symbols mean. With Chinese you actually have to learn the language like you have to learn english or you have to learn Italian.