the composable draw into a draw layer. A layer provides a few different functions, such as: • Isolation for its drawing instructions (similar to RenderNode). Drawing instructions captured as part of a layer can be re-issued efficiently by the rendering pipeline without re-executing application code. • Transformations that apply to all the drawing instructions contained within a layer. • Rasterization for composition capabilities. When a layer is rasterized, its drawing instructions are executed and the output is captured into an offscreen buffer. Compositing such a buffer for subsequent frames is faster than executing the individual instructions, but it will behave as a bitmap when transforms like scaling or rotation are applied. ref. https://developer.android.com/jetpack/compose/graphics/draw/modifiers