The fabric's height z is the gravitational potential Φ at that position — brand mass bends the plane the way mass bends spacetime. Wells are capture basins: a brand sitting in a deep, narrow well holds attention hard; a shallow well is easy to leave.
Saddle points (◇ markers) are the contested frontier between two brands — the position where competitive spend has maximum leverage on switching.
Γ = M/L separates earned pull from bought reach: high Γ brands hold mass they didn't buy with luminosity (dark matter); low Γ brands are bright but light — visible, less sticky.