Why does AI alt text appear automatically on one computer but not another?

You insert a picture in Word and expect its description to appear, because it did on the other computer. Waiting longer may not help. Microsoft's existing AI alt-text FAQ says Copilot+ PCs generate descriptions automatically on the device when you insert an image. On other devices, it says you must request a description from the Alt Text pane or Accessibility Assistant; that request sends the image to Microsoft's cloud model. The same-looking app can leave you with a different next step. Before sending the document, right-click the picture and choose View Alt Text. Check whether a description is actually there, then write or request one and review it. Microsoft says a Microsoft 365 subscription is required for this feature, but a separate Copilot license isn't. Buying that license isn't the remedy its FAQ gives for the missing automatic step. I'd want the empty pane to explain that difference rather than make someone hunt for a broken setting. This is a documentation-based check, not a comparison I've run on two computers. The person receiving the document needs the description; they shouldn't inherit the author's confusion about which machine was supposed to supply it.