In this case the shadow effect looks fabulous!
You won’t hurt your 
, but you can hurt your computer. Specifically burn through on the monitor as it gets too hot.
If you’re removing the cover to engrave then no issue, but if not it’s best to at least try to limit the heat.
The jig is definitely the easiest method. Add a box around your design. Cut just the box out of a piece of cardboard. Drop the laptop into the cut Do not move anything and engrave the design. 100% accurate 