He made each attribute appear as an individual light. This means that a specific likeness was instituted for each attribute (such as the likeness of a lion for Chessed, Kindness) in order to make it possible to gain an understanding of the governmental power expressed in this attribute through the corresponding image or likeness, as will be discussed later.
...through seeing which one may understand that attribute... This is as stated by Rambam (Maimonides): “At the very time when the prophet sees the prophetic vision, its meaning is inscribed in his heart” (Yesodey HaTorah 7:3).This additional point is very necessary. If the Sefirot shone each in its own particular way because of its intrinsic essence, the prophets should certainly have been able to understand the meaning of what they saw. However, since each Sefirah shines in its unique way only because God willed it so, something else was necessary in order for the prophet to be able to understand what was symbolized in the prophetic image – namely, that its meaning should be inscribed in his heart when he saw it. Accordingly, together with his vision of the Sefirot, the prophet is provided with the key to the interpretation of the vision and can thus understand the meaning of these lights in all their detailed aspects.