Minecraft wiki entry for Spectator, associated text: If a player opens their inventory while in Spectator mode, they cannot interact with or use any of the items in it. Likewise, viewing GUIs is possible, but it is not possible to interact with them. If a container uses a loot table to generate its contents, but the loot has not yet been generated, a player in Spectator mode cannot open the container to view its contents. Items in the world also cannot be picked up. Also, the player's head is slightly visible but in a translucent, darker color.