Which IAB Rising Star ad allows engagement through a fixed frame with three units?

The IAB Rising Star ad that allows engagement through a fixed frame with three units is the Portrait. This ad format is designed to capture user attention by presenting a tall, vertical space that creates an immersive experience. Typically, it comprises three interlinked content areas, allowing advertisers to tell a story or showcase different aspects of their brand effectively within one cohesive unit.

The structure of the Portrait format is tailored for user interaction, which can include rich media, video, and social elements, all engaging users in a visually appealing way. The Portrait's fixed frame enhances the likelihood of audience engagement, making it a popular choice for advertisers looking to provide a more involved campaign.

Other formats like the Billboard, Filmstrip, and Pushdown offer distinct layouts and functionalities but do not specifically utilize the three-unit fixed frame engagement that characterizes the Portrait. Each of these formats has its strengths but differs significantly in the way they present brand messaging and facilitate user interaction.