Twitter’s disclosures emphasize the fundamental shift in how users consume online media, moving from the desktop to mobile.

We have been hammering this theme for a long time.

We predicted it before Twitter made its first public IPO filing.Like other online services companies, such as Facebook, LinkedIn, Pandora and AOL, Twitter is feeling the effects of the shift in online consumer behavior from desktop to mobile.

Here are a few choice quotes from the registration statement:

Page 21:

In addition, because a majority of our users access our products and services through mobile devices, we are particularly dependent on the interoperability of our products and services with mobile devices and operating systems.

Page 39:

The number of people who access the Internet through devices other than personal computers, including mobile phones, smartphones, handheld computers such as net books and tablets, video game consoles and television set-top devices, has increased dramatically in the past few years.

Page 37 includes a discussion of the technological challenges involved in tracking mobile use, which impacts advertising and revenue:

We present and discuss timeline views in the six months ended June 30, 2012, but we did not track all of the timeline views on our mobile applications during the three months ended March 31, 2012. We have included in this prospectus estimates for actual timeline views in the three months ended March 31, 2012 for the mobile applications we did not track. We believe these estimates to be reasonable, but actual numbers could differ from our estimates. In addition, timeline views in the three months and six months ended June 30, 2012 exclude an immaterial number of timeline views in our mobile applications, certain of which were not fully tracked until June 2012.

We expect more of the same as we take a deeper dive into the registration statement.

We will also review additional aspects of Twitter’s business in upcoming posts.