Load the XCS file, and set up your bitmap.  I use a rectangle that is set to ‘no output’ to help frame my bitmaps.  The bitmap must be inverted.  The power settings are those for a Walmart “Holiday Time 10 glass ornament" set (SKU 191421095161), but it's questionable whether these are really glass.  At the given power settings the laser will cut through the red paint on the outside but not into the ornament.

Framing is recommended, as is not making your bitmap too large.  If you use more than ~⅓ of the total ornament diameter for the height of the bitmap (shown left-to-right in the XCS view), image distortion will be obvious.

Load ball into RA2.  I found that you must manually rotate the RA2 to ensure the ball is correctly on-axis.  Ensure you wear your safety glasses as the cover must be open, and process.

I used the “Christmas House 10 led string (assorted)” from Dollar tree.   Simply stuff the lights in and let the wire hang out.  When the LEDs are off, it's not obvious that the image is engraved, but when you turn the LEDs on not only does the image shine through but also the whole ball lights up and you can see the shiny wires too.  It's a nice effect.

Using all 10 lights in the string is somewhat overkill in terms of brightness, and the LED set uses two AA batteries which is a bit clunky.  However, the LED set is relatively easy to modify if you have some electronics skills.  All you have to do is cut off the number of LEDs you want to have in the ball, and the wires are insulated with thin enamel that can easily be scraped off.  Then you could use button cell batteries (e.g. size 357 or 303) and put the power inside the ball, or glued to the inside of the ornament cap.  You have to use two cells in series because the 3 volt coin cells (e.g. CR2032) are too wide.  But, experiment.  If you're really handy you could try taking out the little slide switch from the LED set and re-mounting that into the cap of the ornament along with the battery, but that requires some skill.