The icon looks like an eye inside a speech bubble and it was spotted by Jeremy Burge, founder of Emojipedia. 

What's more intriguing is that the symbol has been specifically designed by the tech firm and is not an official addition from the Unicode Consortium, the organisation that manages emoji.

'But the strange thing about this character (which Apple calls "eye in speech bubble") is that it’s not a standard Unicode addition. 

'It can’t be found in Unicode 1.1, or any other version right through to the Unicode 9.0 candidates.'

The Tumblr blog was posted to Reddit, as well as being shared widely on Twitter, and the most popular suggestion was that it would be used to represent Apple's own iMessage feature. 

However, it is unlikely Apple would add the symbol to the emoji keyboard and not introduce it more widely if it did refer to such a significant iOS feature such as iMessage.  

Other suggestions were more unusual, with some Reddit users even comparing the icon to the symbol of the Illuminati. 

This was an 18th-century secret society, set up by Adam Weishaupt in Bavaria, which consisted of influential and wealthy intellectuals. 

It opposed the Roman Catholic Church's control over and sought to 'enlighten' people's minds. 

However, the most plausible explanation was tweeted by Twitter user Erik Veland. 

Using the built-in accessibility tool called VoiceOver in OS X, Mr Veland discovered that Apple's own speech-to-text tool describes the emoji as 'eye in speech bubble representing anti-bullying campaign.' 

This appears to solve part of the mystery, but it is not known what anti-bullying campaign in particular this refers to. 

It is also not clear if Apple is partnering with a specific campaign or starting its own.  

The eye emoji is just one of the new range of symbols expected to launch on iOS 9.1.

Earlier this month, developers with early access to the next-generation software files spotted more than a dozen new additions including a wedge of cheese, a unicorn, taco, a champagne bottle, a weightlifter and a mosque.

Apple's iOS 9 was rolled out to all devices on 16 September and iOS 9.1 could be released as soon as the end of the year. 

The new emoji were released in June as part of Unicode Standard Version 8.0.0. 

A total of 37 symbols were released for use on a variety of platforms in addition to five emoji modifiers that changed the skin tone of the human emoji.

The method of adding new emoji isn’t entirely simple. 

They must first be approved by an organisation called the Unicode Consortium in California responsible for developing Unicode. 

The consortium selects candidates from popular or topical requests and candidates are also picked if there are existing gaps in current emoji - for example, Unicode 7.0 had a tiger, but not a lion.

(dailymail.co.uk)