The overhang is called a jetty and the technique jettying. It's been around since medieval times and is quite common in Europe and especially with Tudor style architecture. You get more floor space on the upper floor while the lower floor doesn't obstruct the street (or in this case, the base of the building can be closer to the tracks). Makes sense in small, tight European villages. It's also said that the upper level protects the walls of the lower level - which were often masonry - from the weather. "Back in the day" mortar wasn't as impervious to the weather as it is now.Disproportionate to me is: The white building on top seems too wide compared to the structure below it.
Some even speculate that it was done because, in the Tudor period, you were taxed by your "land footprint". In towns that was your house footprint. Smaller lower floor = smaller footprint. Personally I think that's a stretch.