True hieroglyphics in dreams are symbols and pictorial representations with hidden meanings, which connect us with a particular stream of knowledge that belongs to the egyptians. Egyptian magic is a system of belief that gave access to the will of the divine and, once the symbology is understood, can greatly enhance our knowledge.
Psychological / emotional perspective: In dreams we will often register a symbol as being a hieroglyphic because it is an idea presented in pictorial form. It is only after conscious thought that the meaning becomes clear and is retained in memory. Hieroglyphics were developed before the written word and, therefore, often represent basic ideas.
Material aspects: Practically, when a dream contains symbols it helps to work out what it looks like. We can then apply the relevance in everyday life. When we have a definite sense of egypt about these symbols we probably need to access old knowledge to help us in waking life. Whether we choose to use ancient magic then is our choice.