Mistakes in training guide?

Hello... studying for 70-410 using the "Configuring Windows Server 2012 R2 Training Guide" from Microsoft Press. On two occasions now I've run into information in the book that seem to me to be mistakes. Either I don't understand something at all, which is certainly a possibility, or there are mistakes in this guide. I'm trying to figure out if someone else has noticed this, and if you have the book, could perhaps give me their thought on specific areas.
Yes, I did check the errata webpage, none are indicated.
Yes, I did check the errata webpage, none are indicated.
Comments
What doesn't seem logical to me is why would I run Invoke-Command $SEASRV1 $script2, instead of just running Invoke-Command $script2? If I'm already connected to a remote session on SEA-SRV-1, $SEARSRV1 says to create a new PSSession to that server. That doesn't make sense, I'm already connected to it!