Solution: Typed or untyped

Here is a possible solution to the task.

Code

my $untyped;
my Int $typed;

dd $untyped;
dd $typed;

$untyped = 42;
$typed = 42;

dd $untyped;
dd $typed;

🦋 You can find the source code in the file reuse-the-container.raku.

$untyped = Any
Int $typed = Int
$untyped = 42
Int $typed = 42

dd reports the two containers differently. For the untyped one it prints just $untyped, while for the typed one it prefixes the declared type: Int $typed. That prefix is exactly the difference a declared type makes.
The empty values differ too. An untyped container starts at the bare undefined value Any, whereas a typed container starts at the undefined value of its type, Int.
After both are assigned 42, the values look the same, but $typed still carries its type and would reject a non-integer value — unlike $untyped, which accepts anything.