1. It could signify that a thread (or original post) is or has gotten very "cheesy".
- or -
2. It could mean that the original poster (or the author of the article posted) sounded like he/she was just whining, so the respondents decided to throw in a little cheese with the "whine".
Now, about the moose (or is it mousse) you're on yer own.
You spelled it wrong. It should be "Møøse" (plural: Meese, Meeses, Møøsad).
I had a Møøse once, but it was unfaithful. It was a mother-lovin' beautiful Møøse until it met the Polish Polar Bears. My Møøse eloped with the head Bear .. the one with all of that nasty Russkie cheese .. and, last I saw them, they were on their way to Disneyland. And I DIDN'T RETURN THE RING ... it's honest-to-goodness 5k gold-tone plated with a .00001 carat diamonique solitaire. Pretty nifty, huh?
BUT I'M STILL STUCK WITH ALL OF THAT CHEESE FOR THE WEDDING RECEPTION!