Opening Title Sequence

Don't know the significance, but presume it was shot vertically and then turned horizontally, clever!

What that could possibly mean bugged me, too, until the sequence where

SPOILER



Gemma submerges herself in the ocean with the intent of suicide, but then changes her mind....presumably bursting back up through the surface.

It isn't very clearly worked out with the objects floating through (?) water, but then they do seem to burst through a surface and spray water as the heroine would have. As this is a pivotal transition in the plot (when Gemma decides to focus her rage toward destroying Simon) I think this is probably what they were reflecting in the title sequence...somewhat.

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Like "Nurse Jackie", "Dr. Foster" has an overlong opening title sequence. After seeing it through once, I fast-forwarded it each subsequent time.