Code / Comments                    Visually
==============================================================================
my $ptext  = $pboard->{'text'};    pboard->text ====+
                                                    |
                                                    v
                                   ptext ====> [ (some IDs) ]
                                                                                
                                                                                
                                                                                
                                                                                
$pboard->{'text'} = [ ];           pboard->text ===> [ ]
# Now they're pointing to          ptext ==========> [ (some IDs) ]
# different things
                                                                                
                                                                                
                                                                                
                                                                                
my $id = my_create($canvas, ...);  pboard->text  ===> [ ]
push @$ptext, $id;                 ptext ===========> [ (some IDs), $id ]
# But my intent was to add $id to
# $pboard->{'text'}!