bearfoil,
That's what I thought it might be, but it seems off to the port side of centre, so I think HN39 is right: it's trunking, not a strut!
Which brings me to my next two questions.
(1) What is the grey-painted member like an inverted "Y" – is it THS-related or fin-related?
(2) What is the complex apparatus that the operative is fiddling with?