As implied by the rest of my comment, that it should be impossible, or at the very least difficult, to identify the subject matter.
Hi Jeremy,
Yes, I assume that would be the case, but just wanted to be sure.
It is a fair question. Like many other words, "abstract" can have multiple meanings and not everyone will have the same one in mind or even agree with some. It is also not a binary definition, i.e., either 0 or 1 (i.e., either totally "obvious" or totally "abstract")... there is quite a range between the two.
But before we embark on deconstructing the linguistic aspect of the word, I think there is one thing that shall be taken into account when it comes to "obviousness" of the images: I presented them in a series, where at least two of them (#1 and #4) contain more of the recognizable elements. I wonder if you just saw, say, #3, or especially #2, alone, would you still
easily know what it is about?
Houston Abstract 2 by
Slobodan Blagojevic, on Flickr
According to Dictionary.com, there are at least 14 different meanings, plus two idioms for the term "abstract."
Meaning #1 seems to be the closest to the one you and some others have in mind:
1. thought of apart from concrete realities, specific objects
The one I have in mind, however, is this one (note the reference to fine arts - emphasis mine):
5. Fine Arts.
of or relating to the formal aspect of art, emphasizing lines, colors, generalized or geometrical forms, etc., especially with reference to their relationship to one another.
Some other meanings are directly opposed to the notion that it "should be impossible, or at the very least difficult, to identify the subject matter." For instance, "abstract" also means (emphasis mine):
6. a summary of a text, scientific article, document, speech, etc.; epitome.
7. something that concentrates in itself the essential qualities of anything more extensive or more general, or of several things; essence.
In other words, even if you recognized it as "modern office buildings" you did so because I successfully summarized it to its essence