All three of the films I deconstructed had completely different ways of entering the film. Evidently it seems that the genre and possibly the year are the biggest contributors rather than the director.
Starting with Harry Brown; it is an action thriller and throws you into the plot almost immediatly, the atmosphere is rushed and dramatic so you get absorbed into the genre. If you take a handful of other action titles such as Star Wars, Quantum of Solace and Lord of the Rings: The Fellowship of the Ring you see the same dramatic opening. This is not necesserily a directors characteristic which is seen in other films he/she has directed but more of what we expect. So from that we can understand that if we were to do an action genre it should have a dramatic opening two minutes.
The Unborn is a horror and follows similar guidelines. It is not uncommon for horror films to begin with a calm 'ordinary day' feel. The reasons being so the plot can develop and/or the audience find themselves in their comfort zone. I think the chilling beginning is more of a modern filming style, older titles seem more natural but the majority of modern day horrors have a very surreal calm to them.