"Enclosure" © DigitalBlasphemy.com
What does this mean for aliens? What it means is that what works for a human may not be the best solution or the solution chosen by an alien. An avian sentient species would need greatly different technology for sitting and control mechanisms (I wonder if a sentient creature that is used to flying, would look to fly beyond the atmosphere sooner than a terrestrial or especially an aquatic sentient species?). A creature that looks more like an octopus than a human would need different seating and control mechanisms as well. Having more fingers, lacking any fingers, having a tail, having more than two eyes, hearing different frequencies, not being able to hear at all, and any number of other physiological differences will affect what the technology will look like, how the species would communicate, and thus affect how we (humans) can find and communicate with an alien race.
And it is possible that there could be some intelligent species that cannot use technology (at least as we commonly define or have commonly come to think of as technology) or which may not have a pressing need for it, or are much slower in developing it because of their physiological limitations. Say, for an extreme example, there are long lived creatures with very slow metabolisms that communicate through touch or biochemical means and who carve out structures within boulders or large masses of rock by secreting acid - such creatures could eventually develop a complex society that discovers complex mathematics, and which ponders the deep questions of "being" and "existence" and the meaning of life; but certain technological development could be very slow - at least the type of technological development that includes physically exploring space and the ability to communicate beyond their planet.
Human Factors and Ergonomics Society. 12 January 2008. <http://www.hfes.org/>
Human Systems Integration Division at NASA Ames. 19 December 2007. 12 January 2008. <http://humansystems.arc.nasa.gov/>