Why not go the whole strech and mention (and explain) Schwartzian Transform

  my @img = map  { $_->[0] }
            sort { $tsort{$Option{thumbsorting}}->() }
            map  { my $seq = m/(\d+)/ ? $1 : 0;
                   [ $_, $seq, (stat "$idir/$_")[7,9], lc $_, rand 1 ]
+ }
            grep { my $s = -s "$idir/$_"; $s and $s > 100 } # Sanity c
+heck. Minimal image size 100
            # convert can't deal with .ico files (yet)
            # Tk can deal with Tiff/NEF as of 804.027_501 with Tk::TIF
+F
            grep m/\.(jpe?g|gif|x[pb]m|png|bmp|tiff?|nef)$/i => @file_
+names;
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and the Guttman Rosler Transform

@out = map substr ($_, 1 + rindex $_, "\0") =>
       sort =>
       map "\L$_\E\0$_" =>
       @in;
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or combinations

# sort file names by the (first) sequence of digits, then by size
my @sorted = map  { $_->[0],
             sort { $a->[1] cmp $b->[1] }
             map  { m/(\d+)/; # sort by digits in file name
                    [ $_, pack "l>l>", $1 || 0, -s $_ ] }
             @filelist;
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