Good points! It would be nice if they disclosed more of their thinking for the DM.This is starting to really bug me about WotC's adventures. They never reveal what an encounter was actually designed for (making one start to think that there was little to no consideration made, just went for what seemed cool... it can't really be that, but the fact that they're not willing to document the challenge, i.e. Easy, Medium, Hard, Deadly for 4 PCs at Level X, makes it appear that way).
Of course this encounter doesn't even fit into that range! So swap it out for a Spectator for a more appropriate challenge. But really what were they thinking?
A spectator does seem like a more appropriate challenge for a 3rd level party ... That said, it occurred to me this morning that maybe they were expecting a single 3rd level PC to investigate rather than the whole party. A gazer would still be a ridiculously easy encounter for a single PC but the gazer might at least get the opportunity to actually do something before it dies.