You can prove that it is a list of references to the contents of the array, not a reference to a list of copies:

@a = 1..3;

# print a reference to each of the values
print \$_ for @a;
SCALAR(0x197c58c)
SCALAR(0x197c598)
SCALAR(0x197c5a4)

# now the list of references - note the same addresses
print for \( @a );
SCALAR(0x197c58c)
SCALAR(0x197c598)
SCALAR(0x197c5a4)

## And finally, modify (increment) the original values 
## through those references. 
$$_++ for \( @a );

# And show the originals are modified.
print "@a";
2 3 4
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