The notion of data having a "shape" has been floating around in my head for years. But how to define shape? A common approach involves concepts like dimensional reduction.
Alternative formal progress has been made in recent years by throwing topological concepts, viz., simplicial complexes, at the problem. AFAIK, there are still no general tools available for data exploration.
This article provides a recent overview.
THE TOPOLOGY OF DATA
Physics Today 76, 1, 36 (2023)
https://physicstoday.scitation.org/doi/pdf/10.1063/PT.3.5157Topological data analysis, which allows systematic investigations of the “shape” of data, has yielded fascinating insights into many physical systems.