Textures controls the Polygon counts in the table assets:
Playfield toys
Targets
Screws
Other similar items.
This affects the smoothness of round objects in the game, like stand-up targets.
The highest polygon count possible in the table models used in TPA. This is the default for this menu now.
A balanced polygon count that compromises on object smoothness in favour of performance.
If you set Textures to the Normal setting, close ups of stand-up targets in Williams' The Machine: Bride of Pinbot appear hexagonal. Other trade-offs also happen that make some playfield elements appear jaggy at distance, and blocky when zoomed in upon.