How could the same Egyptian hieroglyph have both a pictorial meaning and a sound value?

In Egyptian hieroglyphic writing, a single sign could function as both a pictorial representation and a phonetic value through a flexible system of categorization.12

The ability to bridge these functions relied on several principles:

• Logograms: A sign could act as a logogram, where the picture directly represents the object it depicts (e.g., a sun disk for "sun"). This same sign could also carry an extended meaning or a phonetic reading, such as representing the sun god Re or the word for "day".12
• Phonograms: Many signs evolved into phonograms, representing specific sounds or sequences of consonants rather than the object itself. Simple phonemes often derived from the original logograms of the objects they depicted but eventually acquired a purely phonetic character.1
• Rebus Principle: The system frequently utilized the rebus principle, where a picture of an object was used to represent a different word that shared the same or similar sound. For example, if two words shared the same sequence of consonants, the same hieroglyph could represent both, regardless of their different meanings.342

To ensure clarity, scribes often used determinatives—signs with no phonetic value—to specify the intended meaning of a word, helping the reader distinguish between a literal object and a phonetic or abstract concept.1