Microsoft CEO Satya Nadella and Box CEO Aaron Levie had an interesting Twitter exchange on Tuesday, following the announcement that there will be deeper integration between Office 365 and Box’s cloud storage platform.

Shortly after Levie tweeted a link to the post about Box and Microsoft’s new partnership, Nadella responded with the following tweet:

But Nadella’s tweet, which includes a nostalgic, old photo of the box that early versions of Microsoft Office were packaged in, represents more than just his sense of humor. 

For one, it shows Nadella’s commitment to the “cloud,” or delivering software and services over the web.

Satya NadellaReuters/Robert GalbraithMicrosoft CEO Satya Nadella speaks at a Microsoft event in San Francisco, California March 27, 2014.

With today’s new partnership, Box users will be able to create, edit, and share Office files, including Word, Excel, and Powerpoint files, right within Box’s platform.

That means all the editing features of Office Online will also be available, allowing users to essentially complete their work on the web — without having to open a separate software installed in their computer.

In other words, Microsoft is fine with its users ditching its software traditionally sold in a box, like the one seen in Nadella’s tweet, and wants more people to use its online version instead.

But it also shows how Nadella has been turning Microsoft into a friendlier, nicer company willing to partner with its smaller partners. Before Nadella became its CEO early last year, Microsoft was notorious for building software that didn’t always integrate with 3rd party apps. For instance, Salesforce CEO Marc Benioff once said of Nadella’s predecessor Steve Ballmer, “[He] did everything he could to not have a relationship with Salesforce.”

But Nadella has taken a different stance towards competitors, cozying up with them when needed. In recent months, Microsoft has announced new partnership deals with companies that directly compete with it in one way or another, including Dropbox, Salesforce, and Box.

Nadella’s new approach has also earned the praise of many Silicon Valley leaders, including Levie, who recently said, “What Satya has done is really try to drive a new level of openness.” That’s in stark contrast to Levie’s tone in 2011, when he said, “Microsoft is so far behind that it’s not even relevant to talk to them.”