How did the direction faced by animal and bird hieroglyphs help determine reading direction?

In hieroglyphic writing, the orientation of animal and human figures serves as a reliable guide for determining the direction of the text. These signs are typically oriented to face toward the beginning of the inscription.1

Because the script was often written from right to left, the figures usually face toward the right. When reading, one should follow the direction in which the signs are looking to identify the start of the text. While inscriptions were primarily written in this right-to-left manner, they could also be arranged in horizontal rows or vertical columns to suit the architectural needs of monuments, such as doorways or lintels. In instances where texts appear on both sides of a scene, they may face in opposite directions to maintain visual symmetry, with each text oriented toward the figure or subject it describes.1