Final answer:
A Pinnable image is a high-quality, visually appealing image optimized for sharing on Pinterest that encourages engagement and sharing within the platform.
Step-by-step explanation:
A "Pinnable image" as defined by Krista Neher, a marketing expert, is a visually appealing and high-quality image specifically designed to be shared on Pinterest. These images tend to have certain characteristics that make them more likely to be pinned and repinned by users on the platform. They are typically vertical (with an optimal aspect ratio of 2:3 or 4:5), contain clear and compelling text overlays, and often include a call-to-action or branding. The goal of a Pinnable image is to draw attention and encourage engagement through likes, comments, and most importantly, saves and shares within Pinterest.