Iphone 6 : Bad camera quality ?

Hello!

One month ago I had an iPhone of replacement at Apple. I notice that photos are can be poor quality.

The outlines of objects are fuzzy, especially the trees which do not seem clear(net). It looks like the focus is badly managed, as well as the lighting, especially on the photos of landscape.

Could consider yourselves these photos and tell me what the situation is?

(look at the clothes)

And the tree : http://image.noelshack.com/fichiers/2015/40/1443990495-img-2008.jpg (upload with an other host for the size)

Sorry for my bad english and thx!