That's what Raj Singh seems to be saying here:
For example, most of the REST material I've read treats images as indivisible, binary resources. This won't work in the geo field, where images are in the gigabyte and terabyte range and you've got to design services that provide access to portions of those images. However, aside from imagery I don't see much of a problem with using a resource-oriented approach to information access. In fact, in the sensor web arena I think a REST approach makes a ton of sense.
Raj, you're reading the wrong material. No REST architect accepts that the image "file" is the only possible resource. If I had a global sea-surface temperature coverage resource at /sst/current/, I could easily treat individual pixels as resources of their own: /sst/current/{pixel},{line} is just one possible URL form. I could even interpolate to fractional positions within the coverage, or do lat/long: /sst/current/{latitude},{longitude}. Modes of an empirical orthogonal function decomposition (hot topic when I was in school) could be modeled as resources: /sst/current/eof/{n}. Simple temperature slices are another possible set of algorithmic resources: /sst/current/?tmin=28 would be the warm waters that spawn tropical storms. All of the above are RESTful and no client needs to know whether I have a single file or multiple databases backing the resources. Furthermore, a resource-oriented approach scales better than an endpoint-based protocol like WCS. As the number of resources grows, you simply spread them over more servers like Google has done with its Earth and Maps tiles.
There may be geospatial problems that REST can't tackle, but access to arbitrary regions of a coverage is not one of them.
I'm also a bit disappointed to read this:
After all this [research], I think I know what's going on, but I don't think there's any one clear explanation (despite some nice pieces of the puzzle here [1] and here [2]) available, and there has certainly been little effort to analyze the REST architecture in relation to geographic information systems theory, so that's what I'll try to do now.
Of all the great posts and email threads which break GIS web services down in RESTful terms, he picks that muddled Directions article and another that only quotes one of my emails? This trivializes the geospatial community's conversation about REST, one that has been enlightening and amusing us for about a year now. The fact that there will be three REST related presentations at FOSS4G hints at the maturity of the topic.