A product comparison based advert can be risky, especially if you don't have the evidence to back it up, but Nokia has worked very hard at making its camera technology stand out from the crowd. It can quite legitimately claim to be the imaging leader in the smartphone space. The most obvious example of this is the Lumia 1020, but the Lumia 925 is well known for its low light performance, and is a strong all round contender, when compared against other cameraphones based on a 1/3" sensor.
Looking at the advert it is clear that Nokia has chosen a number of scenarios where our own experience would suggest it would perform better than its competitors, but that typical for a marketing campaign.
What's just as important as reality is consumer perception... and it is fair to say that Nokia is well on the way to establishing the idea, in people's mind, that it is an imaging innovator and has the best cameras in its phones. This kind of ad will only re-inforce that impression, so it easy to see why Nokia is continuing to pursue an imaging performance led marketing campaign.
Imaging performance may not dictate which device a person get, but most would agree that it is a factor in the purchase decision, simply because it is one of the most common uses for a smartphone.
Here is Nokia's "Better Photos Every Day" advert:
...and here's Apple's original "Photos Every Day" TV spot: