"The Emperor of Ice Cream" opens by immediately establishing its imperative voice—the speaker's instructions using present-tense verbs like "Call," "bid," "Let," and so on. This gives the poem a ceremonial atmosphere right from the start, the speaker taking on the role of organizer for some kind of ritual (which gradually reveals itself to be a funeral or wake). The first instruction, then, is issued in lines 1-3. Here, the speaker summons the "roller of big cigars" (a "muscular" man). He then says that the man should be instructed ("bid him") to start making ice cream ("concupiscent curds") for the funeral/wake.
Even just in the space of three lines, the poem introduces a number of its key features, in addition to the imperative voice. One of the poem's major themes is finding a kind of aesthetic pleasure in everyday experience, and the poem's language is tuned precisely to make the poem itself, in its way, delicious. So the first line goes straight in with prominent consonance and a little assonance, while lines 2 and 3 add alliteration and much more consonance and assonance too. This involves /l/, /g/, /r/, /k/, /p/, /n/, /s/, and short /i/ sounds
Call the roller of big cigars,
The muscular one, and bid him whip
In kitchen cups concupiscent curds.
Stevens's poetry often delights in the sound of language, and the poem is just as concerned with this kind of pursuit as it is with any literal meaning. This amounts to a performance of sensuality—after all, even a funeral is a kind of show.
"[C]oncupiscent curds" is Stevens's deliberately gaudy way of saying ice cream, which is one of the poem's main symbols. The word "concupiscent" relates to sexual desire, which also ties in with the innuendo of "big cigars" (hinting at male genitalia). And "curds" are coagulated bits of milk used in cheesemaking. Here, they're meant to poetically suggest the thick sensuousness of ice cream. Additionally, while ice cream is cold to the touch—like the dead woman's body—it also symbolizes a kind of revelry in the senses, with its sweet and thrillingly cold taste. It also—like life—doesn't tend to last that long!
These links aren't intended to be explicit, but instead hum away in the background of the poem as the reader makes their way from line to line. Stevens himself thought the point of this poem was to make people conscious of "the excitement of reality"—and there's definitely something visceral and exciting about the way these three lines begin.