Let's say you make two snapshots. One of them has layer 1 turned on and layer 2 turned off, the other has layer 2 turned on and layer 1 turned off. If you "Download all" of "composite", it downloads the composites of all the snapshots, but only with the layer settings of the current snapshot. So, in the example above, both downloaded composites would have layer 1 on and layer 2 off. It seems that the download all doesn't take into account the layer differences between the different snapshots.
Let's say you make two snapshots. One of them has layer 1 turned on and layer 2 turned off, the other has layer 2 turned on and layer 1 turned off. If you "Download all" of "composite", it downloads the composites of all the snapshots, but only with the layer settings of the current snapshot. So, in the example above, both downloaded composites would have layer 1 on and layer 2 off. It seems that the download all doesn't take into account the layer differences between the different snapshots.