They could be Virgins 'Preferred' seats.

I've just flown return with Virgin Atlantic from Manchester > New York and booked Premium cabin for better seats. When it came to choosing our seats the only three seats together were their 'Preferred' seats which I had to pay extra for. I struggled to establish how they differed, and having now flown with them I'm still struggling to understand. The only thing I can think of is that the Preferred seats might get served their food before the remaining seats, other than that there was no difference, the actual seats were exactly the same. Of course the front row of three seats has the extra leg room, something to do with being able to have a baby cot?

I was tempted to not choose my seats and chance that the three 'Preferred' seats might still be available anyway upon boarding, but didn't want to take that chance.