Weird behaviour with parent operator and array constructors

[mikhail-barg]

While implementing the parent operator in my .Net Jsonata port, I stumbled upon the following test in the suite. It says that applying the query

Account.Order.Product.[`Product Name`, %.OrderID]

to the Invoice dataset should result in a flat array,

[
  "Bowler Hat",
  "order103",
  "Trilby hat",
  "order103",
  "Bowler Hat",
  "order104",
  "Cloak",
  "order104"
]

which indeed it does: https://try.jsonata.org/3IY-yuZkE

But why? Isn't the braces here are the explicit array constructor? Consider changing the query to one without parent operator, e.g.:

Account.Order.Product.[`Product Name`, SKU]

This would result in a nested array:

[
  [
    "Bowler Hat",
    "0406654608"
  ],
  [
    "Trilby hat",
    "0406634348"
  ],
  [
    "Bowler Hat",
    "040657863"
  ],
  [
    "Cloak",
    "0406654603"
  ]
]

Aren't the queries are just the same in the aspect of result structure?