With my crazy punctuation idea, one could continue this thought. Polonius could be pointing out the location of the Lord to Hamlet instead of pointing out Hamlet to Rosencrantz and Guildenstern.
I mean – Hamlet doesn’t need to be pointed out to Rosencrantz and Guildenstern, presumably they know how to recognize him.
Often, in performance, this line has a dismissive quality – like Polonius is done with Hamlet and he’s tossing this line off to shake Hamlet off – to foist him off on Rosencrantz and Guildenstern perhaps. Maybe he would have given them a formal introduction but instead just points Rosencrantz and Guildenstern in the right direction and stalks off. I can’t think of any other way I’ve ever seen it done.
Some Shakespeare education colleagues told me about a production in which Polonius, as the Prime Minister, is so busy, he’s constantly being presented documents to sign and things to do, calls to take, etc. In that case, this line could act as a hurried passing introduction.
Or it could be a last attempt to connect with Hamlet. Probably not, though, but it would be worth an experiment.