Actually, no, it's not just a tricked out mobile home. Apart from size, it's constructed like most regular homes, but even higher quality. Most tiny houses are built using stick framing, same as regular houses, with 6" exterior walls and lots of insulation (higher insulation level than most regular homes), have level of interior trim that is similar to but usually better than regular homes. Also most tiny houses are built so at least part of structure has very high ceilings, 11 to 12 feet, which greatly adds to feeling of spaciousness. Tiny homes cost much more per square foot than regular size homes, but of course are much cheaper overall. Even though they're usually built on wheeled trailers and can be moved, they're not built for constant moving.

In short, tiny homes are built to "feel" like a regular home, even though much smaller. Mobile homes, in contrast, are not, generally feel cheap and light, much different experience.