On Confluence Cloud, third‑party apps like Aura render content inside isolated iframes. Due to this sandboxing, images displayed inside these app iframes cannot use Confluence’s native fullscreen/lightbox behavior, even when the underlying storage uses <ac:image>. The same images, when placed directly on the page, open fullscreen as expected, so customers perceive this as a regression from Server/Data Center.

This is a limitation affecting all Marketplace apps, not a specific vendor bug, and there is no supported API for apps to hook into the native image viewer. Customers with app‑heavy content (e.g. Aura Tab Collections) report this as a migration blocker because many screenshots and diagrams are unreadable without fullscreen. Current workarounds—duplicating images outside macros or linking to separate pages/attachments—are cumbersome and do not scale.

We request a supported, documented mechanism (API/event) that allows apps to open the native Confluence image viewer for a given image/attachment from within their iframe, while preserving security isolation.