As mentioned before, the goal of the pixel craftsman is twofold. On one hand he tries to make the apparent resolution finer. On the other he struggles to represent what it is he's drawing. The two goals are always in friction. Let's look at these two pieces of high art I just devised:
I posit that both images represent the same idea. A man shitting in a sine arch.
The first image has a high apparent resolution because the lines are perfect and also - more importantly - because as the viewer looks at this they cannot discern a pixel grid, they cannot see the single pixel almost at all.
In the second image the single pixel is very apparent. If we zoom in a bit more in fact,
That there is a very confined space in which to represent the human figure in its volumes and shapes means that the more colors and clusters we employ, the more the underlying grid of the image has to show.
The particular ambitions of the pixel artist, at this level, are paramount. If one wishes to convey a fully rendered object as realistically as possible, it cannot be helped that the apparent resolution will be lowered. As clusters of pixels come to interact, places where the pixels 'line up' and betray their resolution are inevitable. The trade-off is that the rendered object appears more realistic, with whatever benefits the artist might assign to that. Let's look at a schema:
Here we have a simplified model of aesthetic motivation for the pixel artist. It isn't very different from the motivations of artists in other fields, but there are some additional considerations to inspect that are very pixel-art relevant. On this point I'd like to say that I am not using the above terms as they're usually meant in the history of art. I am appropriating the terms slightly so the layman can follow along.
With abstraction I mean that the realized object of the piece of art does not clearly refer to something in the natural world.
With realism I mean that the artist is attempting to render his object lushly enough that the viewer will interpret it relatively literally.
With symbolism I mean that the artist is attempting to convey objects with clear higher functions without allowing for literal interpretations.
Try to think of your favourite pixel artists, and place them in a space within the triangle. Try to assign specific works by them in the triangle and then make specific observations about how each artist is prioritizing their two goals: hiding the grid/increasing apparent resolution and conveying the volume, light and surface of their intended object literally. You will find that artists near the top of the triangle will have very high resolutions and very simple/naive objects, whereas artists near the left end of the triangle will have resolutions of moderate fineness while their objects will be meticulously shaded. Art towards the right edge of the triangle will both have very low resolutions and very simple shapes!
The realist pixel artist will often make large areas where the resolution is practically infinite (like the shoulder of the girl in the above Lazur bit) and then place single-pixel, low-resolution level detail on various specific pieces to rejoice in the pixel-ness of his work just a little (the highlights on the hair here for example). The ambition of the artist leans heavily towards removing the grid, but doesn't frown away from going 'hey, here's my pixel, do you love it? I love it!' once in a while.
The complete abstractionist has effectively destroyed the pixel in his work, it is in the place of Ideal Space. It could be vector art or anything else that isn't shackled to the limitations of a monitor really. We do not have examples of such pixel artists really because as you might imagine, that goal would be very self-defeating. However there are a few artists whose work is very very close to vector smooth, like Panda or Ilkke sometimes, but you can tell they're pixel artists at heart because they can't contain themselves from putting in pixel-level details in a few places after all.
The symbolist pixel artist creates art that is very informed about its being made of pixels and wants the viewer to know it also. All of the modern 'retro art' fits in that edge of the triangle for me, with the artificially low resolutions and the flat and fat pixel character designs. These retro artists are not interested in pixel art technique to make the resolution higher, they are interested in invoking nostalgia on the older viewer or to inform the younger viewer of the semiotic particulars of older video game art.
I do not judge any of these motivations. It is however my belief that regardless of which way the artist might feel drawn towards, for their art to maximize its capacity as pixel art, they should reconcile their different aspirations so as to retain a place within the relative center of the triangle (the grey circle area). The realist artist should not attempt to completely abolish the pixel-level detail and end up with a blurry mess of a piece with 250 colors in it. The symbolist artist should not completely forego the attempt to make their pixel clusters achieve their ideal state. The abstractionist should not make their resolution that fine so that in the single pixel no longer feels like it belongs.