Another mystery Nokia Lumia has emerged, ahead of the company's Mobile World Congress event. My Nokia Blog has spotted an odd looking Lumia in an ad designed to showcase the Lumia 920 on Dutch carrier KPN. The unknown yellow Lumia appears to be a mix between the Lumia 822 and the Lumia 620. Nokia previously surprised us with the introduction of its low-priced Lumia 620 at LeWeb back in December, so it's possible the company has plans to introduce another budget Windows Phone. It could also be nothing at all, just a mockup or even a digital edit.

The ad comes just a week after another mystery Nokia Lumia design was revealed in a patent. Filed back in December, it appears to show a phone that has an angled back similar to concept designs that Nokia has worked on previously. We're still expecting to see at least one Lumia device at Mobile World Congress later this month. Nokia is planning to introduce the Laser, EOS, and Catwalk this year as part of its Windows Phone 8 push.