It seems there's more to come in that area. If you look at the signals in the first picture you'll notice both are mounted high with the provision for a third head, this leads me to believe it is a future home signal. The signal out of the Westminster facility is outfitted to govern 3 tracks while only carrying 2 signals for 2 existing tracks. Perhaps there is a plan to continue double tracking the main in addition to the Wachusett station and layover leads?
Note: After looking more closely at the second photo, I see that the same is true for that set of signals as well.
Moderator: Massachusetts Bay Transportation Authority, Brightline Trains
Avatar:3679A (since wrecked)/3623B (now in service as 3636B).