Although it's only sixteen lines long, Stevens makes us pay a lot of attention to each word in "The Emperor of Ice-Cream." A cigar, in this case, is not just a cigar. Ice cream may be a simple treat, but there's more to it than just sugar and cream. And the emperor, in his typically tyrannical way, is demanding that we look at him in a different way too, even if he isn't real.
At first glance, it might just look like a silly poem, but when we look closer we begin to notice patterns, symbols, and repetition of key words and ideas that make us think twice. The emperor is different for a reason, and he's not just an "emperor of ice-cream" because Stevens thought it sounded cool.
So there's quite a bit of untangling that we have to do here, whether we're looking for symbols, themes, or just trying to keep track of all of the enjambment that's going on. Also, Stevens isn't making the process very easy, since we have a lot of ambiguity and unusual phrasing (typical hallmarks of a Stevens poem).
Still, once we do get our bearings and begin to understand that the main idea here is to be in the moment the way we are when we enjoy life, that we should make the most of it before we're dead, we start to appreciate the language of the poem a bit more. More than that, we can appreciate the journey of reflection it took to get us to this idea.