Recently, GitHub enrolled me into one of their beta features, a new site wide navigation on github.com. I noticed something odd in their navigation sidebar. Their “Upgrade” link uses the “Outbox” icon.

The next day, I noticed that twitter.com uses the same icon for Sharing tweets.

This got interesting and I started looking for web pages where this icon was being used. Google’s Bard uses it to export responses.

Safari uses it to share a web page.

Font awesome suggests that it’s the “upload” icon.

iOS uses it for sharing a screenshot.

Google Chrome uses a variant of it for “upload” functionality.

LinkedIn’s iOS app uses it for post sharing.

So, I’m not sure what the right usage for this icon is. If someone familiar with it could enlighten me, that’d be great.