Instagram has added a new Easter egg to its smartphone application, allowing users to change the app icon to the original Polaroid-style camera.

There are 13 different icons to pick from, including Instagram's pre-launch icon from 2010, the two classic icons that were used between 2010 and 2016, and a range of different takes on the current icon.

To change the Instagram icon, follow these instructions:

1. Open the Instagram app
2. Tap on your profile in the lower-right corner
3. Tap on the menu icon in the top-right
4. Tap on Settings

Now you need to swipe down as far as you can from the top of the screen right to the bottom. Swipe far enough and there will be a brief confetti animation, and the new app icon page opens. Now just tap on the icon you want.

It looks like the app selection is only available for October, as Instagram states: "...this month we're inviting you to change your app icon to your favorite". Instagram teased these instructions in a tweet earlier this morning, explaining the instructions in emoji form, below.

As well as the new icon-changing Easter egg, Instagram is also marking its 10th birthday by tweaking how the app talks users out of posting potentially offensive comments on the photos of others.

The app already challenges users when they try to post a comment that appears to be bullying in nature; now it will serve up an additional warning when people repeatedly attempt to post potentially offensive comments.

Instagram said in a blog post today: "Since launching comment warning, we saw that reminding people of the consequences of bullying on Instagram and providing real-time feedback as they are writing the comment is the most effective way to shift behavior. These new warnings let people take a moment to step back and reflect on their words and lay out the potential consequences should they proceed."

Now, if a user types a potentially offensive comment a pop-up window appears stating that the comment may go against Instagram's guidelines. The app then says: "You've tried to post several comments that look similar to others that have been reported. If you post this comment anyway, it may be hidden from others...If your comments go against our community guidelines, your account may be deleted."

It has been a year since the first version of this system rolled out, and in that time Instagram says it has "seen a meaningful decrease in negative interactions in both comments and captions."