To hopefully answer a few questions.
This started as an optically clear crystal glass block.
The technique is referred to as Sub-Surface Laser Engraving.
A 3D computer model is created as a point cloud at a density suitable for the SSLE machine to be used.
The SSLE machine is used to create the dots within the glass.
The high power laser is precisely focused at a known position.
Each laser firing produces a micro-fracture within the glass.
How the beam is moved and how quickly depends on the machine.
To do a one-off like this is very expensive because the cost is dominated by machine setup.
I used a UK company with UK based SSLE machine.
A batch can be cheaper especially if you are willing to offshore production and use smaller glass blocks but you need to be very cautious about model copyright and be willing to wait for surface mail delivery.
More information about SSLE here:
http://www.engravinglaser.net/Sub_Surface_Laser_Engraving.html