Yes that is exactly right.  It is supposed to be said as a question.  Usually repeated 2 or 3 times, with the feeling of confusion. 

Several years back my wife (Dawn), myself and our two kids traveled to the Oregon coast on a vacation.  While there, we visited the Cape Mears light house.  As we were driving from the highway to the light house there were a couple of signs for the Octopus Tree.  Apparently Dawn did not see the signs. I said that I wanted to see the Octopus Tree.  The kids thought it was stupid to go see a tree.  My wife could only say “Octopus Tree???” She just kept repeating it several times.   It was one of those family things that seems hilarious at the time, but difficult to explain the humor to someone who is not part of our weirdness and not having been there.  It has become a statement of confusion for our family.  If there is a time when something is confusing, the appropriate thing to say is.... “Octopustree?” pause for effect then  repeat “Octopustree?”