#!/usr/bin/perl

use strict;
use warnings;

use YAML;

my $arr = [[IMG0001 => [{y => 0,
                         filename => 'new value',
                         x => 0,},
                        {y => 0,
                         filename => 'cel.jpg',
                         x => 10,},],
           ],
           [IMG0002 => [{y => 0,
                         filename => 'batman.jpg',
                         x => 0},
                        {y => 10,
                         filename => 'robin.jpg',
                         x => 10,},],
           ]];

splice @{$$arr[1][1]}, 1, 1;

print Dump $arr;

__END__
---
-
  - IMG0001
  -
    - filename: new value
      x: 0
      y: 0
    - filename: cel.jpg
      x: 10
      y: 0
-
  - IMG0002
  -
    - filename: batman.jpg
      x: 0
      y: 0
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