Pick a soil on the texture triangle and set how wet it is; a field of exactly that earth stretches out. Poke, rake, pour and smooth it — what you displace heaps into the rim, then settles the way that soil settles. Damp sand holds a sandcastle; saturate it and it slumps; dry clay cracks.
The field is a height-field of soil. A poke presses a dish in; that soil is heaved up into the rim (mass conserved), then the surface relaxes — any slope steeper than the soil can hold topples downhill until it settles. Dry sand stands at ≈33°, so it slumps wide; clay's cohesion holds near-vertical walls. Wetness adds capillary suction: a little water lets even sand stand steep (the sandcastle), too much and the pores carry the load and it liquefies and runs out flat. Dry clay loses water and cracks. Pour drops fresh soil that finds its own angle of repose; rake draws parallel furrows; smooth wipes it flat again.