Strange photo of Lee Kuan Yew’s birthday

In a report on the 91^st birthday of Singapore’s former prime minister, Lee Kuan Yew, the Straits Times had this rather curious photo which accompanied its report:

The first thing one notices is that the picture, of Mr Lee celebrating the occasion with some of his former staff, has a completely darkened or black background.
What room or place was this to have such a background?
On closer inspection, however, it seems that the dark backdrop was photoshopped.
If you look closely, you can see the outline of a different shade of black around the top of some of the heads of the people in the photo, especially above the man and three women to the extreme left of Mr Lee in the photo.
Was the background blackened out for some reasons? What would these reasons be?
If the contrast is enhanced, the picture looks like this:

It is also strange that in the Straits Times report, it was able to name all the men in the photo but of the women the newspaper says, “[The] women in the picture were not identified.”
The Straits Times credits the photo to Mr Heng Swee Keat’s Facebook page, but does not say who provided it with the names of the men in the photo, and why the names of the women were unavailable.
Incidentally, Mr Heng’s Facebook posting of the photo does not include the names of those in the photo, including the men.
Neither the Straits Times nor Mr Heng disclosed where the photo was taken.
Nonetheless, we wish Mr Lee a happy birthday.