Yeah, I'm not sure what world you have to live in for "three-mouthed monster" to be a more obvious meaning for that glyph than "stacked crates".

But I think I might like to visit.

I see you haven't gotten to the 4th paragraph of TFA...

"口" = mouth, not crate

"品" is a stack of mouth characters

I read the whole article, thanks. Do you think it's possible that more than one square or rectangular thing may exist?

According to kanjinetworks.com that is, in fact, what the etymology boils down to:

> Square-shaped object (tripled) → high-quality goods spread throughout a protective container (compare 舗 and 販) → quality; counter for goods; (person's) character; grade; value.

http://www.kanjinetworks.com/eng/kanji-dictionary/online-kan...