An array slice is not a datastructure, it is simply a list of elements from the array. If you recall from the docs, when you do something like this:

my $ref = \ (1, 2, 3);
print ${$ref}, "\n";
[download]

The output will be '3'. You've just created a reference to an anonymous scalar value, which happened to be the last value of the list. If you had said,

my @ref = \ ( 1, 2, 3 );
print ${$_}, "\n" for @ref;
[download]

Your output would be '123'. That's because the \ operator is distributive to each element in the list; and @ref receives as values three references, each to one of the anonymous scalar values in the list.