Slack on iPhone Duo: what Apple shows

In the photo Apple published, Slack fills the inner display of iPhone Duo, in landscape, in two columns: on the left, the list of conversations, with its buttons at the top; on the right, the open conversation, with its controls on the side and the tab bar at the bottom. In a message, a row of photos runs under those controls; the text and the input field stop short of them.

Last checked October 2, 2026

Photo of iPhone Duo open, in landscape, with the Slack app in two columns. On the left, on a purple background, the list of conversations, with buttons at the top. On the right, a conversation: two photos side by side, the second one running under the controls on the right edge, then messages and the input field. On the right edge: the time, buttons, the tab bar, and a magnifying glass. — The conversations column has a purple background. Along the right edge, from top to bottom: the status bar, two grouped buttons (headphones, a list), a purple + button, then the tab bar (a selected house, speech bubbles, a bell, three dots) and a separate magnifying glass. At the top of the conversation, the person’s name sits in a horizontal capsule; in the message, the second photo runs off the edge of the screen. Image: Apple Newsroom

What it illustrates

Where the bars go · Rule 8
Only the column along the edge of the screen has its controls on the side; the list’s buttons stay above the list, as in a split view (list and detail).
Where the bars go · Rule 7
The grouped buttons at the top, the tab bar held at the bottom of the same column.
Don’t stretch · List and grid · Safe area and backgrounds
A DuoApps recommendation, drawn from this photo: what scrolls can pass under the controls on the side, as long as every element can come back into the safe area; what doesn’t scroll, like the input field, never goes there.
Don’t stretch · Carousel · Safe area and backgrounds
The same recommendation for a carousel: a row can pass under the controls, provided every element can come back within reach.

What Apple says about it

Apple names Slack, along with Netflix and Zoom, among the third-party apps already taking advantage of the foldable design to offer immersive experiences on the large display.
Apple Newsroom
According to the photo’s caption, on iPhone Duo Slack “brings a user’s whole workspace into view.”
Apple Newsroom
In a split view, only the detail column, along the edge of the screen, has its controls on the side; the controls of another column stay with it, horizontal, like those of the list in Mail.
“Raise the bar”, 3:36 · HIG, Vertical controls · Developer article, Optimize bars for vertical presentation
Interactive controls go within the safe area. A full-width background can be combined with inset scrolling content; every interactive element then stays in that inset part, so nothing is covered.
“Prepare your app”, 6:37 · “Design for iPhone Duo”, 7:06
By default, an item with an icon moves to the side; a text-only item, or one made of a custom view, stays in a horizontal bar.
“Raise the bar”, 6:52 · “Raise the bar”, 7:13 · Developer article, Organize items in your bars

What the source doesn’t say

Slack’s reasons: the newsroom describes what the app shows, not why it’s built this way.
The motion: the photo is a still. The row cut off at the edge suggests that it scrolls and that the second photo can come back into the safe area; the photo doesn’t show it, and Apple doesn’t comment on content passing under the controls.
The outer display: no photo shows Slack with the device closed.
The other poses: the inner display in portrait, the device partially folded, Slack in Split View next to another app.

Sources

Apple unveils iPhone Duo, Apple Newsroom, September 9, 2026
Raise the bar with iPhone Duo, Apple Developer, Tech Talk
Designing for iPhone Duo, Apple Human Interface Guidelines, September 9, 2026
Preparing your app for iPhone Duo, Apple Developer Documentation
Prepare your app for iPhone Duo, Apple Developer, Tech Talk
Design for iPhone Duo, Apple Developer, Tech Talk
Slack icon: App Store, Slack Technologies, Inc.