iPhone 7 picture leaks
Unlike the iPhone 6S and 6S Plus pictured here at an Apple media event in San Francisco in 2015, some analysts say the iPhone 7, expected to launch later this year, won't prevent Apple's smartphone sales dropping to 2014 levels. Reuters/Beck Diefenbach

Apple suffered its first ever double-digit decline in the first quarter of this year, with sales down 14 percent year-on-year, according to Gartner. Its stock price suffered as a result, and investors and shareholders are now looking at fall this year, when the next generation of iPhones are typically released, to see if the company can turn this around.

However, if a leaked image of the iPhone 7 turns out to be real, it looks like Apple won't be making any major design changes for its new smartphones.

The image, which was published on Chinese social media site Weibo, shows the rear cover of what is purported to be the 4.7-inch iPhone 7. The image shows a design which is instantly recognizable but with the two horizontal, white antenna lines from the current generation of iPhones incorporated into the curved top and bottom of the cover.

The other feature of note is the camera, which appears to show a redesigned lens housing which once again protrudes from the rear cover. Some earlier rumors claimed Apple would feature a dual-lens set-up for its rear camera on the iPhone 7, but this image would appear to rule that out — though that feature could still appear on the larger iPhone 7 Plus.

The relatively minimal redesign of the rear cover ties in with what some analysts have been saying about Apple's plans for the new iPhones to be released this fall. KGI Securities analyst Ming-Chi Kuo, who has deep supply chain sources and a good track record of predicting Apple’s future plans, says the company is preparing a slight refresh of its range this year before a significant upgrade in 2017, including an all-glass design and wireless charging.

Apple typically introduces significantly different iPhone designs every two years, with the so-called 's' upgrade introduced every other year refining that design by adding performance improvements and extra features. Earlier this year, Apple reintroduced a smaller 4-inch smartphone called the iPhone SE, prompting some to speculate that the phone maker could be set to call this year's new models the iPhone 6SE and iPhone 6SE Plus.