5 Things We Learned From Marissa Mayer's Tweet Last Night

Late Tuesday night Yahoo! CEO Marissa Mayer, a finalist and runner-up for Time's 2012 Person of the Year award, visited the 5th Avenue Apple Store in New York City.

to Twitter that read: "The 5th Avenue Apple store at 11pm. Wow…" The tweet also included a Flickr photo taken from the stairwell of the store as she headed downstairs.

If a photo speaks a thousand words, here's what this one tells us:

1) Mayer doesn't have the most up-to-date Apple iPhone. The Yahoo! CEO's Flickr photo reveals that Mayer still owns an iPhone 4S. As Flickr user Pondage commented, "Time to upgrade to the iPhone 5!"

2) No one seems to notice Mayer is there. The photo shows customers and Apple employees going about their business, checking out the latest devices and having discussions with one another; no public tweets made note of her presence either. Mayer isn't the first tech exec to go unrecognized in New York this month, as Apple CEO Tim Cook strolled through Grand Central Terminal with NBC's Brian Williams without anyone taking a second glance.

3) Mayer chose not to use a filter on her Flickr photo. Just seven days prior to the tweet, Yahoo! fought its way into the photo-filter fray, joining a space with Facebook-owned Instagram and Twitter. "So good Flickr iOS is finally here," wrote Mayer at the time of release.

4) Yahoo and Apple may be warming up to each other. Mayer's snapshot of an Apple store came on the same day Instagram created - what many are calling – Instagate, an online riot where Instagram users were outraged at the company's changes to its privacy policy and Terms of Service. Apple is also featuring Flickr in its App Store as the Editors' Choice.

5) Yahoo is playing offense. Mayer's tweet, which silently promotes Flickr's iOS application, also came on the same day Yahoo!

encouraging them to download the company's upgraded mobile app. As Twitter user @JesseRedniss pointed out, "Nicely timed, @Yahoo... way to play the offensive move" (after Instagram users threatened a mass exodus).

— Written by CNBC's Eli Langer. Follow him on Twitter at @EliLanger.