Vexx,
if ($2 = $nick) is if the person using the !seen command types in their own name.
if ($2 = $me) is if the person tries to perform the !seen command on the bot/user running the script. It\'s just a bit of fun. It could be left so it just says they are on the channel, but it just adds a bit extra to the script to give a humerous answer if a user \"!seen\'s\" themselves or the bot/user running the script. :)