You cannot create an image in low res and expect it to display in HD. Images ghouls ALWAYS be created at the highest DPI and size possible, covering yourself for ANY medium you may want to use it for. You simply can't upscale a small, low Dpi image and expect it to look good. If you approach design from a print side, wanting to use the image for web, then DPI matters. MOST people who don't do design for a living will be very confused by this notion of resizing and resampling. OK, I guess my wording was incorrect. DPI doesn't matter for web viewing, but it certainly matters for creation of the HD image. It works in relation to the canvas size. If you crate a large canvas at 72 DPI, or a small canvas at a high DPI, it's the same thing. People need to understand the relationship and difference between the two. The article confuses that a bit even when it tries to explain it. I'm not disagreeing with you, I'm just saying it's not entirely accurate to say DPI doesn't matter. People will misunderstand that, unless they know about relative size. We live in a world where everyone person with a pirated copy of Photoshop fancies themselves a graphic designer. It's made my life a living hell for many, many years. I've been a designer and ran a commercial print shop pre-press department for 25 years. It's people misunderstanding how it works it a annoyance, especially when your expected to make HD out of web images. ---------- You are correct. The iPhone 6 zooms in on the image when rotated. It doesn't handle background images the same as the iPad, so I believe the square theory for res is wrong, just because of the handling. Setting the wall paper in landscape mode first doesn't fix that. it doesn't even allow you to do that.