Samsung's (NASDAQOTH: SSNLF) marketing team is no stranger to aggression -- the Korean tech giant has used its massive ad budget to target Apple (NASDAQ:AAPL), its products, and its fans in recent years, repeatedly mocking the company in a series of television ads.

While Samsung's smartphone market share has (and continues to) lag behind Apple's in the U.S., its marketing campaign has been effective at generating buzz, and has even drawn praise from Apple executive Phil Schiller.

Yet, the company's latest ad reeks of desperation, and suggests that even Samsung believes Apple's next iPhone will be a runaway success.

Samsung: We've been here for years
Samsung's latest ad features two men in a coffee shop discussing Apple rumors (watch it here).

"iPhone might be getting a bigger screen," one says, before a voice-over chimes in. "You know that thing you've been waiting on for like two years, and how it's supposed to be awesome, and how it's gonna blow your mind?"

That "thing" is the iPhone 6. In recent months, numerous reputable media outlets and various supply chain leaks have reported that Apple's upcoming iPhone 6 will feature a screen larger than its predecessor. Though nothing remains confirmed, most observers -- including, evidently, Samsung -- seem to have taken it as fact.

Samsung's ad is delivered in a mocking tone, identical to its prior clips that have painted Apple's customers as brain-washed drones. But this time, Samsung's marketing team is unable to offer up a compelling reason to buy its products, except to say that Samsung has been offering phones with larger screens for years.

Apple could steal Samsung's best customers
That may be true, but if Apple's next iPhone does feature a bigger screen, Samsung's size advantage won't matter for too much longer.

I've explored the question of whether or not Samsung should fear Apple's larger iPhone in the past. Ultimately, I didn't think it was much of a cause for concern. Although Apple's ecosystem and its customer loyalty may be greater than Samsung's, there's evidence to suggest that the larger Android ecosystem can be just as sticky, and Samsung's customers have been getting increasingly loyal in recent years. Samsung now retains some 77% of its customers according to Statista.

But its latest ad suggests that Samsung is well aware of what a larger iPhone could do -- when the size of its screen is no longer a distinguishing factor, Samsung may lose its biggest selling point.

Samsung's struggles
Financially, Samsung has begun to struggle, although the company blames recent performance weakness and disappointing guidance on competition at the low-end. In emerging markets, particularly China, generic smartphone vendors have begun to offer cheaper competing devices as good as (or perhaps better than) Samsung's products.

If Apple delivers a larger iPhone this fall, it could weigh on Samsung's high-end Galaxy handsets, phones that have so far dominated the market for expensive Android devices. Analysts have seen Samsung's recent missteps as an opportunity for Apple -- Barclays, when it upgraded Apple shares to overweight earlier this month, cited Samsung's weak preliminary results as a reason to buy Apple shares.

With Apple shares having crushed the market since the company last reported earnings, hope appears to be running high for the company's next flagship handset. While it may be tempting to write-off insane sales projections as overly optimistic, Samsung's willingness to target the device -- months before it's likely to be unveiled -- bodes well for Apple.