Icon Size
Width and height in the same units as MapsGL JS icon.size — pixel dimensions for the laid-out symbol quad (see web SymbolStore.layoutIcon: w/h from PaintStyle.iconSize).
Instanced gridded renderers convert these to Mercator half-extents using GridLayerRenderer.mercatorHalfExtentsFromJsIconPixels with JS_REFERENCE_WIDTH_PX (40px reference); width/height are multiplied by device android.util.DisplayMetrics.density there so physical on-screen size scales with DPI.
innerWidth / innerHeight are relative to JS_REFERENCE_WIDTH_PX for Mapbox icon-size in GridLayerPaint.asStyleJSON.