حصول صورة الشيء في العقل
The coming-to-be of a thing's form in the intellect.
Suppose you had not understood what a tree is, but then came to recognize it. Considered as an acquisition, a meaning has become present to your mind.
A form here is not necessarily a visual picture. It can be an intelligible meaning or recognition. For example, justice can be understood without a single pictorial representation.
This formulation emphasizes the acquisition of a mental form, not a physical object entering the mind.