The Pen Pal 4-in-1 Makeup Pen by Alleyoop is a versatile cosmetic product that combines eyeliner, highlighter, lip liner, and brow pencil all in one convenient pen. The reviewer, Hadia, was immediately drawn to its cute and nostalgic design. They found that the pen dispenses each shade easily with a simple twist of the center. The brow pencil and eyeliner applied smoothly, surprising the reviewer. They also enjoyed using the highlighter on the tip of their nose. Hadia mentioned that this pen is perfect for travel, as it combines multiple products into one. Overall, the Pen Pal 4-in-1 Makeup Pen by Alleyoop received positive feedback for its convenience and ease of use.