What purpose does the the latrine "secret" in Starcraft 2 "Zero Hour" mission have?

While playing the Starcraft 2 mission "Zero hour", i found a latrine at the top center of the map, in between of two Zerg bases. When i clicked it three times, it flew away and a "Secret found!" text popped up.

Does it unlock something? Or is it just an easter egg?

Solution 1:

It's an easter egg. Tauren Marine!

Supposedly, if you unlock it, you can see the outhouse flying around in space during some of the cutscenes (though I can't validate that, as I have yet to see it)

Solution 2:

Playing the "Maw of the void" level, you can watch out in space the occasional outhouse rocketing through. I usually saw this flying on the bottom of the map. Please note this is a background graphic, and can only be seen while looking into the open space places of the map. it will not appear over the platform your units are based on.