Bradbury has a straightforward writing style that seeks to evoke a sense of wonder through two seemingly opposed concerns: the careful construction of mundane details and a sharp eye for vividly capturing imaginative flights of fancy. Combined, they create Bradbury's signature style, finding wonder in everyday life by using fantastic / unrealistic elements to highlight the vagaries of human nature. Often, this means the stories are built on simply constructed sentences --declarative, often distanced from the subject it describes - with dramatically timed lapses into a more florid, poetic writing style when a character comes to grips with a new experience, such as the rocket flight of "The Rocket".
Given the nature of many of the stories in The Illustrated Man, there is a seriousness in tone that is also reflected in an emphasis on reportage - Bradbury's style is dispassionate when describing the moral lapses of his characters, allowing the readers to feel their own distance and apply judgment as they see fit. Bradbury makes moments of judgment purposefully difficult: revenge is justified by the empathic story of Willie Johnson's slaughtered parents in "The Other Foot", even as readers know it would further a vicious cycle; the lure of space is evident in Doug's attitude towards his Dad in "The Rocket Man," even as he describes how his mother suffers from this.
Bradbury's forays into humor in these stories are similarly dark, best epitomized by the harsh satire of "The Concrete Mixer". The language here is florid in a typical Bradbury move - but instead of expressing awestruck wonder at new experiences, it encapsulates the disgust and fears of Ettil Vrye at how an Earthian culture will destroy all that's good about Mars. Similarly, the horrific nature of death in space is captured vividly in the poetic language of "Kaleidoscope" and "No Particular Night or Morning".
The short story collection format poses certain problems for both author and reader. One way that Bradbury helps make the story coherent is by keeping his style of writing fairly consistent from story to story. The framing sequence is weaker here than in two other notable short story collections by Bradbury, The Martian Chronicles and Dandelion Wine, as it comprises of a Prologue, Epilogue, and a handful of brief vignettes about the tattoos. Thus, it's easier to see the stories as separate entities and more difficult to find a unifying factor beyond the surface conceit of the tattoos. However, the repeated thematic concerns and mostly consistent voice of these stories - third person omniscient, moral in its seriousness but holding back judgment - provides a stronger coherence for the careful reader and helps in understanding The Illustrated Man as a product of its era.