It has been discovered that few Retina iPad mini units are showing image retention issues, no one knows exactly how many units are affected by this.
The discovery was made by Marco Arment of Instapaper fame, who originally developed a grid test to detect a similar problem in the Retina MacBook Pro models. Quite a lot of Retina iPad mini owners have run the grid tests on their units and have found the issue to persist, whereas there are those users as well who don’t seem to be experiencing this issue even after running the grid test. Its unclear if the issue only affects displays manufactured by a certain supplier. LG and Sharp are believed to be manufacturing displays for the Retina iPad mini.
Recently it was rumored that Sharp’s IGZO Retina display panels were suffering from LCD burn-in issues which were causing the delay in the tablet’s release. The problematic panels are also believed to be the reason why there’s such limited supply of the latest iPad mini. Image retention has been cited as a potential issue as well, but its temporary and not permanent like LCD burn-in.
Given the fact that most Retina iPad mini customers are currently within return windows, they can take their unit back to an Apple Retail Store and get it replaced. Apple replaced Retina MacBook Pro models when they were facing similar issues, so its quite likely that the company will adopt a similar policy for its latest iPad mini.