> The sky above the port was the color of television, tuned to a dead channel.
That first sentence characterizes the novel's diegetic (in-narrative) setting by giving the sky a property of an alternate medium (television). Unlike gentler rhetorical assertions such as simile, the declaration that the sky possessed a property of television suggests that the setting--like the intra-diegetic setting of the (Morrocan) beach in which an unnamed adversarial AI imprisons Case--is also a media construct in which the reader is imprisoned.
In other words, the media topology structuring the novel's outermost narrative is a recursive formation of one medium inside another medium and this structure is timeless. It's merely recursion.
However, fully understanding the literary (as opposed to narrative) significance of such a structuration depends upon knowing what television was and why any of its channels might be "dead" as opposed to "live".
A useful point of comparison can be found in William Shakespeare's _As You Like It_ (II.VII.139-143)
All the world’s a stage,
And all the men and women merely players;
They have their exits and their entrances,
And one man in his time plays many parts,
His acts being seven ages. [. . .]
The significance is timeless, drawing power from the assertion that life is in fact lived on a stage. On the other hand, the description is also time bound (as well as culturally circumscribed) depending as it does on the greatly diminished (since Elizabethan England) medium of live performance.EDIT: Fix predicate in first sentence. Formatting. Change "at" to "a" in penultimate sentence.