Your line may be more readable, it's not returning a reference to the string. It's returning a reference to itself.

use 5.10.0;
use strict;
use warnings;

sub foo {"A string"};

my $object = bless [];

my $retVal1 = \$object->foo;
my $retVal2 =  $object->foo;
   $retVal2 = \$retVal2;


say "$retVal1: $$retVal1";
say "$retVal2: $$retVal2";
say  $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$retVal2;
__END__
SCALAR(0x893c2c8): A string
REF(0x894d1f4): REF(0x894d1f4)
REF(0x8d9b1f4)
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