I'm no designer (though I have put together a handful of icons in my day), but the part about too much realism in an icon seems fairly obvious. Are overly-realistic icons actually a problem? If so, a few real-world examples might have been more useful than the fully rendered house icon, which seems far-fetched.
Also, I don't really agree with the comment that the icon shouldn't include any details other than the bare minimum needed to convey function. Things like shading/shadows can give icons a more polished look. For example, I wonder if the author would argue that the red/yellow/green indicators in his home button example shouldn't have shading or specular highlights because that's just adding unnecessary detail.
Lots of things are intuitively obvious -- but when articulated clearly, it is possible to understand them more precisely. That ay you can use the knowledge in a rigorous way, not just an intuitive way.
Maybe so, but this article doesn't even give us enough info to enable anyone to be rigorous. The takeaway was to "make your icons detailed enough, but not too detailed". Whether it's obvious or not, what is actionable about that advice?
Like I said, maybe a few more realistic and/or real-world examples would have made the actionable takeaway clear. As it is, it's just another blog post stating the obvious -- IMO.
If you search around the various different icon sets there are actually quite a few that that the article's author would probably deem "too realistic".
That being said, I think that often they are targeted more towards things like section header graphics than tiny buttons so I'm not sure how much of the criticism is applicable.
I have one of those Chinese mp3 players (branded mp4 player), it had all these realistic icons that really made it look crap (besides the fact the interface was slow and clunky as well).
Also, I don't really agree with the comment that the icon shouldn't include any details other than the bare minimum needed to convey function. Things like shading/shadows can give icons a more polished look. For example, I wonder if the author would argue that the red/yellow/green indicators in his home button example shouldn't have shading or specular highlights because that's just adding unnecessary detail.