"Sustained Attentional Loop" - Does it apply to bike pictures? Handlebars, crank, saddle.
Yes. Any two dimensional image to begin with. Making a two dimensional look three dimensional is another craft, related more to perspective control. The "western" eye wants to read left to right, then down. Bright parts surrounded by darker areas grab attention, just like our innate lust and pleasure looking up at a star filled night.
The artist though can't afford us to loose attention and go outside of a frame - he/she does not have the luxury of vast space like nature to scan back and forth and in depth and in wonder. An old concept of vignetting is tool to help here.
So a circular loop of bright, handed over to dark, then bright again is deployed. The eye motion around the picture is far from limited to capturing three bright parts (but it is a minimum for triangulation). Very physically large art works especially in Renaissance era used the technique but gave visual clues to connect it all - like fingers pointing, draping cloth, eye contact, etc. etc.
A good photograph from our conditioning is also based on a good painting.
When it comes to bikes, the absolute classic on a drive side two dimensional image is a silver stem, silver crank, silver seat-post. The first impression triangulation is made. It is totally classic.
The bike designer though needs to occupy with rest of the visual space, and that I think, not even Shimano scores (always) the high points and have made errors.
I remember when I first joined this site, there was a thread about retro pro bike builders would hack up things like Alivio hubs and match them with XTR or XT or LX parts, for something they considered aesthetically pleasing and coherent and balance.
Balance is a sort of funny concept, but in arts it's easy. You put the image in a mirror and / or cut the image in half vertically and butt it's opposites together, and / or cut the image horizontally and do like wise. You tend to look for volume of colour here, rather than absolute position. On a bike we are not free to modify the position of things, but volume of colour can be adjusted.
Balance also requires some sort of fulcrum point, so on a bike, it's typically something central and usually the chain set - more so the outer most chainring I have found like umpteen others. A black outer ring will marry well and again is classic to what I think is a good looking bike respecting the black extreme three point human contact points and help tie it altogether.