Sherlock, The Abominable bride, opening scene explanation

Question

In the Sherlock, Abominable Bride episode, a particular scene caught my attention. In the opening scene just when Mike Stamford and Dr. Watson are heading to meet Sherlock, in the backdrop we can see a man with curly ruffled hair searching through some books, in dim white light. The entire area is candle lit(Victorian era), so how come only this specific room has dim white light?

Also from that angle the person in the room seems to be the modern day Sherlock. Is this scene a deliberate attempt(clue) to show that it is all going on in Sherlock's head?

Answer 1

In my opinion . . .

The Victorian parts in this episode take place exclusively in Sherlocks 'Mind Palace' i.e. they are purely a figment of his imagination.

This quote from IMDB seems to suggest that:

Sherlock Holmes and John Watson of 1895 are in a carriage to meet Mary Watson. Watson asks Holmes about his wife. When Sherlock is vague with him, Watson shouts, "Sherlock, tell me where my bloody wife is, you pompous prick, or I'll punch your lights out!" Notice during this line that Watson's moustache is gone and he is wearing his modern day clothes. It is a glitch in Sherlock's mind palace, perhaps.

Source : IMDB Trivia

So, if the above premise is correct then the blue light in the scenes described are an early visual clue to show that this is 'all in the mind' of Sherlock. The blue light does suggest that within the room/cell it is the present day, yet outside it is the Victorian England.

Answer 2

I remember watching the scene and just re-watched it. It is definitely daytime, but the scene takes place in a mortuary or the basement of a hospital. The other room appears light blue by contrast and it must be getting sunlight. The opening scenes have some sort of a filter on them and daylight appears bluish not yellow/orange. This matches the light in the other room. I doubt there is any significance of the man searching through books. That room is present in the same scene, not some sort of a flash-forward to the future.