Manipulation list of lists from sql query before listview

MIT App Inventor Help
14

I did do the test with "is a ...." and:

  1. the query result is a list (confirmed) and I can pick single value by item number
  2. the query values are NOT list, string or dictionary

From this thread:
https://community.appinventor.mit.edu/t/text-in-label-enclosed-with-square-brackets/74228
@ABG wrote

The (square brakets) wrapper is the default conversion in AI2 when taking an entire list and converting it to text.

but when I do "is a string" check result is false

Said the above, I can check Json but what exactly related to the query, list and conversion of list item to ?

I keep on reading