The stall is designed every morning
A flower market is not decorated. It is arranged, and the arrangement is redone from scratch every single day before the first buyer walks past.
The stall has no walls, so its edges have to do the work a wall would do: the tallest stems at the back, the buckets at a height a hand can reach without bending, the whole thing angled slightly towards the pavement rather than square to it, because the pavement is where the eyes are.
What looks like abundance is a set of decisions about height and interval. Colour is grouped so that no single colour is stranded alone, and the gaps between buckets are kept narrow enough that the whole stall reads as one object from the far side of the road.
This is a design practice done under time pressure by people who would not use the word design for it. The flower sellers of the city bowl have been doing the same layout in the same place for a very long time, and the reason it survives is not nostalgia — it is that the layout works.
By mid-morning the arrangement will have been broken by buying, and it will be rebuilt again in the afternoon without anyone writing down a rule.