[4] Its lyrical themes touch on death and the decomposition of the human body—"Fluorescent Grey" is the name lead singer Bradford Cox gives to the color of dead flesh.

Cox wrote on the Deerhunter blog that he "especially like[s]" this early version of "Dr. Glass," as he feels the band did not adequately capture "the atmosphere and creepiness" he desired for the song's final incarnation.

Cox recorded "So Many Bodies" after experiencing a panic attack induced by a photograph he saw in The New York Times, showing an Iraqi girl hunched over her dead mother's corpse.

Pitchfork writer Marc Hogan considered the EP "clearer and less abrasive than Cryptograms musically," and "a triumphant document of a stubbornly visionary young band with the world still spread out before them."

He found the EP's musical style to be a "delightful deviation" from Cryptograms, as it gives listeners an opportunity to step "back from all things fiery and furious" characterized by that album.

PopMatters music critic Josh Berquist wrote of the EP's opening track, pointing out the contrast of Cox's "lucid reflection on loss…[and] the morbid imagery of bodies in decay" sung "over an incongruously bright and chiming rhythm", which he found made "such beautiful invitations to bloody eviscerations unnervingly captivating."

Jeff Klingman of Prefix Magazine considered the final track of Fluorescent Grey, "Wash Off", to be the only song which "channel[s] the aggression that peppers Cryptograms' first half."

In his review for Tiny Mix Tapes, writer Chris Ruen said that Fluorescent Grey "is a bit rushed" in terms of structure, which he feels "detracts from one of Deerhunter’s particular strengths: constructing a dynamic, organic listening experience."