Apple's (AAPL 0.64%) brand isn't what it used to be. According to communications firm Millward Brown, Google (GOOG 1.25%) (GOOGL 1.27%) now has the most popular brand in the world, surpassing Apple, which occupied the top spot in each of the last three years.

While this won't affect Apple's financial results, particularly in the near future, it does serve to reinforce a common criticism of the company and simultaneously highlight a weakness with one of its long-standing strategies.

Very different valuations
When it comes to valuation, it's indisputable: The market expects much more from Google than Apple. The latter's price-to-earnings ratio has been less than the broader market's for many quarters now, and though it has begun to tick up in recent weeks, remains quite low, particularly compared to Google's.

Google is currently trading with a P/E near 28, almost twice Apple's 14.5. There are many potential reasons to explain this discrepancy, but Apple's commitment to secrecy definitely plays a role.

Google flaunts its experiments with self-driving cars. It talks about curing death and building real Androids. There's Google Glass, Project Aura (the modular smartphone), and the acquisition of Nest -- the first step in a Google-centric home. Video game consoles, drones, weather balloons, fiber Internet -- Google makes no attempts to hide its moonshot bets. Most of these projects are very likely to fail, but think of the possibilities! You're not just buying an advertising machine -- you're buying a call option on the future (or so Google's management would have you believe).

With Apple? None of that. It may be that Apple is planning to revolutionize wearable computing, mobile payments, and perhaps the television -- but investors just don't know. Apple's management is evasive, occasionally dropping hints, but never offering anything concrete. When you buy a share of Apple, you know you're buying a company that depends almost totally on the iPhone, with a declining tablet business and a few other projects on the side. The excitement that Google exudes simply isn't there.

Apple's Tim Cook had promised new product categories across 2014, but here we are, almost halfway through the year and nothing new has been unveiled. Is the iWatch coming this year? A revolutionary Apple TV? Perhaps. Or maybe not. The analysts and supply chain leakers who have been reporting on these devices have been predicting their imminent release for, quite literally, years.

Is its commitment to secrecy weighing on its brand?
Its refusal to divulge its future plans may be weakening its brand image, according to Millward Brown, which says that Google's "boldness" helped it to leapfrog Apple, as the later's product portfolio is beginning to show signs of being stale.

Of course, there are advantages to its secrecy -- it keeps competitors on their toes, and Apple's brand value hasn't exactly plummeted (it's in second place, after all). Longtime Apple shareholders aren't likely to care. Commitment to secrecy is a core part of Apple's philosophy; there's nothing new there.

But it's still a disappointing trend for the iPhone maker. After surpassing Apple's iOS in smartphones and tablets, Google has now overtaken it in brand image as well.