If you want help, you will need to show us the actual code you're running. Also, please don't post screenshots where the simple source code and text output of Perl suffices. That makes it much easier for us to reproduce the problem and thus helps us help you better.

I suspect that, for some unshown reason, you have something like the following in your code at line 13:

my $p = sequence(64,48,3);  # make test RGB image
my $win = $p->imag2d();
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The documentation of PDL::Image2D claims that the usage is not as a method but as a separate function:

use PDL::Graphics2D;
my $p = sequence(64,48,3);  # make test RGB image
my $win = imag2d( $p );
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