The word 一览无遗 is formed by sequentially combining the characters 一 (one), 览 (to look), 无 (without), and 遗 (to leave behind). The literal construction pairs 一 and 览 to mean "one look", and 无 and 遗 to mean "nothing left out", resulting in a compound phrase that directly conveys the idea of seeing everything completely in a single glance.