Just like every written language, hieroglyphic writings needed conventions to keep writings consistent and readable. For instance English is always read left to right.

Hieroglyphic writing was written in columns or rows. Reading direction is determined by the direction that human and animal figures faced. Reading starts from the direction that figures face and continues in the opposite direction.

Hieroglyphs could be written left to right.			But they were usually written right to left.
	Columns were read down as we would read lines down a page. The Egyptians liked symmetry. If hieroglyphs were inscribed in a column, they would often inscribe the same text in the opposite column, except with the writing reversed.