A Chinese chop is a signature, and placement of the stamp has to be in exactly the right place to harmonise with the artwork.
(It’s also important where you place your signature and the name of the author). Sometimes a piece calls for a cartouche, and sometimes not. If you scroll down you’ll see two other occasions where I felt that my chop provided the right finish.
While I was doing my kimono series, I had a Chinese chop carved. (Yes, I know, kimonos are Japanese and the chop was Chinese, but the old scripts are similar and this was the only way I could get one). I had it made by Guangwha in Soho. They did a translation of my name which sounds like “small forest”. Here is a page showing how it was derived.