What does this button in the Firestorm Citadel do?

I've been doing the Firestorm Citadel quite a lot now, practicing taking out Lord Vanaduke before I attempt a Shadow Lair run. I see this button hidden under a few boxes:

Unfortunately, I forget exactly where this is, but as you can see (over the minimap), I'm on depth 27. This button does not have an obvious effect on the rest of the level. I've completed it with and without pushing it, and never noticed a difference.

What does this button do?

Solution 1:

Apparently the button used to do nothing. It was a bug, a leftover, which was why most forum threads you'll find say that it does nothing. Check the date on the thread, and you'll likely find the game has been updated since then.

Speculation around the web says this button was given a purpose around the time of the missions update. Since then, pressing the button adds a ghost block here:

Shooting it removes all the blocks on that path, allowing you to get here: