Safety with a Laser is important and I am surprised that anyone would've been allowed to operate one at a craft fair.
I finally had mine up and running and just a 10 watt machine. Even at that, I have tried to set it up safely. The fumes, dust, smoke ,etc are an issue for me and I am exhausting outside. My enclosure has an orange acrylic window for viewing and the laser is surrounded by a shield. I have a steel honeycomb and a sheet under where cutting. Of course, I have fire extinguishers at hand.
LASTLY, YOU DO NOT WALK OFF AND LEAVE IT RUNNING UNLESS YOU HAVE A CAMERA TO MONITOR IT REMOTELY.
Just like other hobbies, there is a lot more to it than one thinks.
As an aside, I really enjoy my laser and all the learning to use it. I am surprised at home much it takes to figure out the right setting for cutting or engraving. I still use my scrollsaw but enjoy a change of pace.