The teaser image of the Galaxy S4 that Samsung released on Monday

New York’s Radio City Music Hall will be packed to the rafters on Thursday night for an event that is garnering almost as much hype as an Apple launch. Samsung Electronics will use the event to unveil the Galaxy S4, the successor the best-selling Android smartphone of 2012, the S3.

But the Korean company may already be trying to play down inflated expectations of just what it will be announcing when its executives take to the stage. On Monday, it released an image of the S4 cloaked in shadow with the Samsung logo barely visible.

The shape suggests that the device will closely resemble its predecessor — much more so than the S3 over the S2.

It’s probably an understatement to call the S3, launched just 10 months, a runaway success. By January, the device had sold more than 40m units; Apple’s iPhone 5 had sold 47m by comparison.

Samsung’s Monday teaser image hints at evolution rather than revolution. Perhaps the company is trying to manage the expectations of consumers who are hoping for a reinvention of the wheel with every new device.

Though Samsung has done an Apple-esque job of keeping images and details of the S4 from leaking, some of the S4’s specifications are already all but certain.

The S4’s screen real estate appears set to grow five inches, from the 4,8-inch screen on the S3, with resolution jumping from 720p to 1080p (the same as that flat-panel TV in your living room). This means the S4 will likely pack a pixel density of 441ppi compared to the S3’s already-impressive 306ppi.

A speedier processor (details haven’t leaked) will replace the 1,4GHz model found in the S3 and the camera looks almost certain to gain five megapixels over its predecessor’s eight.

Across the board, in fact, Samsung looks set to take the brute force approach to the S4 — the numbers are bigger so the device must be better, right?

The phone will almost certainly come with Android 4.2 overlaid with a newer version of Samsung’s TouchWiz skin.

One of the most notable features of the S3 is “Smart stay”, where the handset uses the front-facing camera to detect when a user is looking at the screen and prevent the display from going to sleep. With the S4, Samsung is expected to expand on this idea with a feature that will allow users to scroll through Web pages and other large bodies of text and images using the movement of their eyes alone.

Samsung’s answer to Apple’s voice assistant Siri, called S Voice, will no doubt also get a (much-needed) update.

Critics of the S3’s cheap and plasticky rear will be disappointed that it appears the S4 will keep the plastic enclosure rather than moving to a unibody design favoured by competitors such as Apple and HTC.

The Samsung Galaxy S4 will be up against phones like the iPhone 5, left, and the HTC One

It’s the HTC One, announced last month, that is the phone Samsung really has to best here, though. The One, which is expected to go on sale in South Africa in coming weeks, is encased in an aluminium unibody shell and packs in some of the most impressive processing power yet seen in a smartphone.

Of course, the One’s predecessor, the One X, was an excellent match for the S3. Fortunately for Samsung, HTC showed itself to be not nearly as good at marketing, something the Taiwanese company has promised to rectify as it takes the One to market.

The question is whether the S4, if it does turn out to be an incremental update, will leave Samsung fans levelling the same sorts of criticism that Apple experienced when it launched the iPhone 5. The US company was criticised for being too conservative and lacking innovation in the update to the iPhone 4S.

The S4 could serve as a reminder that dramatic innovation on an annual basis is not always possible.