According to Phys.org, mathematicians are viewing billiards as a model computer. The piece frames the idea with a question: when is a billiard ball not a billiard ball? The answer, in short, is when mathematicians get involved and treat the game as an abstract computing device.
The framing is meant to illuminate the relationship between computers and prediction. Making the game into a model computer lets mathematicians ask how far ahead it is possible to see in such a system, and where that foresight runs out. The billiard ball becomes more than a sports object; it becomes a tool for thinking about predictability.
Since this piece draws on a single source, there are no conflicting accounts to compare. The article stands alone as an explainer of how a game of balls on a table can double as a study in computation.