Samsung's (NASDAQOTH: SSNLF) earnings report could be ugly. According to The Wall Street Journal, the Korean tech giant's chief financial officer told a group of reporters on Wednesday that the company's upcoming earnings report isn't "look[ing] too good."

As a major competitor to Apple (NASDAQ:AAPL), competing with the company in many of the same markets, Samsung's poor results could be cause for concern for Apple shareholders.

Samsung is a diversified business, but focused on mobile
Unlike Apple, which makes only a handful of products, Samsung is an extraordinarily diversified business, offering everything from refrigerators to televisions.

But increasingly, Samsung's mobile products have taken center stage. Like Apple, Samsung's smartphones and tablets now account for the majority of the company's revenue and profit. Last quarter, of Samsung's $8.2 billion operating profit, $6.2 billion was derived from its mobile division.

If Samsung is indeed struggling, it is likely because its mobile business may not be doing as well as analysts and investors had hoped.

Samsung's problems may stem from emerging markets
The Journal notes that analysts at KTB Investment & Securities recently lowered their forecast for Samsung's earnings due to weakness in the emerging markets. Although Samsung is commonly known for its high-end Galaxy handsets in the west, many of the phones it sells are budget models aimed at emerging markets.

Samsung's cheap phones allow it dominate emerging markets like China. According to research firm Counterpoint, Samsung is the largest seller of smartphones in China, with an 18% market share. Apple, in contrast, comes in fifth, with just 10% of the market.

If Samsung's results are the byproduct of poor emerging market performance, it may not reveal much about Apple's current quarter. Although Apple still offers cheaper, older models of the iPhone, it has nothing that competes directly with Samsung's lower-end Galaxies. The Galaxy Star Pro, for example, retails for around $100 in India -- Apple's iPhone 4S is several times more expensive.

At the low-end, Samsung is facing growing competition from Asian vendors like Lenovo, Xiaomi, Oppo and ZTE. Offering handsets running the same, or similar versions, of the Android operating system that powers Samsung's Galaxies, these low-cost vendors may be stealing Samsung's emerging market customers.

Apple investors should watch Samsung's results
Nevertheless, Apple investors should still be mindful of Samsung's earnings when the company provides second quarter estimates next month. If the smartphone and tablet markets are contracting, particularly at the high-end, it wouldn't be a good sign for Apple's business.

Last quarter, the iPhone accounted for more than half of Apple's revenue, while the iPad brought in nearly 17%. Factoring in iTunes, which is largely a derivative of iPhone and iPad sales, more than 80% of Apple's revenue is a byproduct of its mobile device sales.

Apple shares have been on a tear recently, rising more than 17% in the last three months. Much of that has likely been due to the company's aggressive capital return program, and hope for future products, including the iPhone 6 and iWatch.

But fundamentally, Apple is still a company that depends on sales of tablets and smartphones. Samsung isn't in an identical situation, but it's the closest proxy, and if Samsung is struggling, Apple may be in a similarly precarious position.