tweaked wording about VMs

README.md

@@ -22,9 +22,11 @@ guest Linux OS, which is configured to automatically run some process
 when it starts.  Nothing is running in it -- you can think of it
 like a hard drive.
 
-The easiest way to get an image is to *pull* it from a *registry*. Docker
-has a default registry built in. Our VM is running Ubuntu 16.04, and it turns
-out there's an image available with this OS on it! Here's the command to run:
+The easiest way to get an image is to *pull* it from a *registry*.
+Docker has a default registry built in. We have, at times, used a
+course VM that is running Ubuntu 16.04 for a common baseline, and
+it turns out there's an image available with this OS on it! Here's
+the command to run:
 
     docker pull ubuntu:16.04
 
@@ -176,8 +178,8 @@ command that's present on the image. Let's see this in action:
     docker run ubuntu:16.04 /bin/date
 
 That should print the date in the container. It's probably in UTC, while running
-/bin/date on your VM should print the date in Eastern US time (EST or EDT). You
-can also specify options:
+/bin/date (or the equivalent) on your computer should print the
+date in Eastern US time (EST or EDT). You can also specify options:
 
     docker run ubuntu:16.04 ls /var