Aren't metals in general (and aluminium in particular) excellent heat conductors?
Yes aluminium is a good heat conductor, which is why it is used as a heatsink to dissipate heat from electronic components like the CPU in you laptop. The idea of the aluminium stand for your laptop is to raise it up from the desktop surface, allowing air to pass between the gap and extract the heat from the aluminium stand as your laptop heats up with use.
