From the little I know, phone companies do not develop their cameras...at best they might draw the basic specs and contract the project to an external company (there are quite a few of those around...Aptina, Omnivision etc.), normally they just buy a module with its SDK and API's etc.
Lenses, if they are branded ones, come as part of the module and they pay for the badge (Zeiss or whatever)
Not saying this is the case here but I doubt that Nokia developed the camera or the sensor from scratch by themselves
There are several interviews on YouTube with someone from Nokia's design team that mostly corroborate that: Nokia participated in the design with unnamed technology partners (though the names Toshiba and Toshiba do float around), including Nokia setting the specifications for the sensor.
However, the interviews do claim that the lens in this case is a custom design by Zeiss for the special needs (higher angular resolution than any previous phone camera module), so I would not be too quicPk with the suggestion that the Zeiss branding is simply "badge engineering". After all, for a relatively high volume and low size component, it can make sense to pay for the best in design skill, and high quality materials. The lens design is apparently unusual, with five aspherical elements. Nokia also claims to have been involved in developing the algorithms for the custom signal processing chips.
In short, this is very far from an off-the-shelf phone camera module like the ones from Omnivision and Sony and such in so many phones.
P. S. to put it another way: the unit volume of lenses for phones like this can easily be a thousand times greater than for a good MF lens, or a hundred times greater than for a high end SLR lens, so that even allowing for the great differences in selling price, the total revenue from sales of one such lens design can be comparable to that for one MF or high end SLR lens design. Then it can make sense to spend a comparable amount on the design and other fixed costs associated to producing a good phone camera lens. Economies of scale can be a wonderful thing.