Here's an example that uses a Toplevel to fake a messagebox, and ->after for the timing.
Fill in the toplevel with whatever message you want. I sort of tried to simulate what you say you want to do.
If the scraper is a long running process, take a look at Tk::IO which would run it in a sub-process and just fetch the results.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11126974
use warnings;
use Tk;

my $fakebox;
my $oldstatus = '';
my  $vertical = 0;
my $mw = MainWindow->new;
$mw->geometry( '+500+600' );
$mw->Button( -text => 'Exit', -command => sub {$mw->destroy},
  -font => 'courierbold 24')->pack;

$mw->after( 1, \&checker );
MainLoop;

sub checker
  {
  my $new = localtime(); # replace localtime with your scraper results
  if( $new ne $oldstatus )
    {
    $fakebox and $fakebox->destroy;
    $fakebox = $mw->Toplevel();
    $fakebox->title( 'Message Box' ); # really fake it :)
    $fakebox->geometry( '+300+' . (300, 400)[$vertical ^= 1] );
    $fakebox->Label( -text => '  Notice  ', -font => 'times 24',
      -fg => 'white', -bg => 'red3' )->pack;
    $fakebox->Label( -text => $new, -font => 'times 24' )->pack;
    $oldstatus = $new;
    }
  $mw->after( 3000, \&checker );
  }
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