I would like some opinions about the texture of this Lincoln cent. I'd like to know whether the mottling seen at the bottom between the stems of the wheat ears is undesirable, or just an artifact of how the picture was taken.
It appears to be just natural toning. I don't see it as detracting in any way. But what matters is if you do. And since you asked, it must bother you to some extent. So if you are considering buying this coin, you may wish to reconsider. Small feelings like this seldom go away, they will eat at you and bug you forever about this coin. So in these cases it is best to listen to the whispers of your inner voice
I have rejected coins based on that kind of small misgivings. However, I'm actually very impressionable when it comes to toning so if the opinion of an expert is that it's not objectionable, it wouldn't bother me. I just couldn't tell if it was an artifact of the picture taking process. Sometimes you can appreciate detail in a picture that isn't at all apparent when you look at the coin directly. It has a similar area of toning on the obverse also.