Sprites used in the reflection system — including those from sprite sheets and sprite atlases — work correctly with all three reflection types. The reflection cameras capture whatever is rendered on the specified layers, so atlas-packed sprites, animated sprites, and spritesheet-based characters all appear in reflections and interact with the obstruction system without any special setup.
No atlas configuration is needed. If a sprite is visible on a reflected layer, it appears in reflections. This works automatically for all sprite packing methods.