while (@found < $pics_to_find * 30) {
  last unless @found_galleries;  # exit the loop if there are no more
  my $gallery_content = get(pop @found_galleries);

  while ($gallery_content =~ /.../) {
    ...

    # why use "yes" and "no"?  why not just a true value or a false value?
    next if
      $limit_img_size eq "yes"
      and !some_size_constraint();

    push @found, ...;
  }
}