What's happening: After opening modestly in the red on Wednesday following the release of mixed second-quarter results, shares of Discovery Communications (NASDAQ:DISCK) continued to drift lower throughout the day to close down more than 11%. 

Quarterly revenue rose 3% year over year to $1.65 billion, which translated to a 21.6% decline in adjusted net income to $316 million, and -- thanks to share repurchases over the past year -- a more muted 15.5% decrease in adjusted earnings per diluted share to $0.49.

Analysts, on average, were anticipating slightly lower earnings of $0.48 per share, but on higher revenue of $1.67 billion.

Why it's happening: Keeping in mind International Networks comprised more than 48% ($801 million) of Discovery's total revenue during the quarter, Discovery's top line would have grown a much more impressive 11% excluding the negative impact of foreign currencies.

Discovery also signed three big agreements during the quarter: One to secure exclusive TV and multiplatform rights to the Olympics from 2018 to 2024, another to acquire full ownership of Eurosport, and a third in the long-term renewal of its existing deal with Comcast.

For the full year 2015, however, and on a currency-neutral basis, Discovery now expects total revenue excluding currencies to grow in the "high single to low double digit range," while adjusted earnings per share should rise in the "low double digits." By comparison, Wall Street was modeling revenue growth of 3.7% including currencies to $6.5 billion, and 4.8% growth in adjusted earnings including currencies to $1.74 per share. Considering Discovery's more comparable 3% revenue growth in Q2 already resulted in the aforementioned low-double digit increase on a currency neutral basis -- and taking the (very rough) assumption that exchange rates stay roughly consistent -- that indicates analysts' were slightly more optimistic in their models.

But it also doesn't help that fellow entertainment juggernaut Disney simultaneously fell more than 9% today after it missed analysts' second-quarter revenue expectations. For that, Disney blamed declining ad sales and modest subscriber losses at ESPN. More troubling to Discovery's case -- and as fellow Fool Anders Bylund wrote earlier today -- is that Disney made it clear those losses were "more likely due to American households dropping cable TV services altogether than opting out of ESPN specifically." 

Of course, that doesn't mean Discovery is doomed; the company is working diligently to not only identify streaming media platforms in which it can participate, which grew to include Sony's Playstation Vue and Hulu, but also to build its repertoire of leading content that can easily be leveraged across its global distribution platform. According to CEO David Zaslav, around 85% of Discovery's channel content easily translates from the core domestic market to emerging markets like China and Brazil, which should help it secure growth and market leadership for years to come.