A glyph is a hieroglyphic symbol that signifies the signifier. The glyphs in 'Object typeface' are a collection of symbols from the shadows of three objects (a paper cup, a paper ball and a plastic bottle) in various angles. The glyph would not function without the object, neither does the other way around.
"[...] setting letters on a page was simply a matter of ink or no-ink, on or off, 1 or 0 [...]"
Dexter Sinster, “Mathematical Typography” (After Donald Knuth, 1978).
paper cup, paper ball, plastic bottle, typeface, screen and keyboard, 2018