As lovely as the suite looks, the bed does look on the skinny side. I did find a side-view picture on another website. The armrest does not move, and the top seems to flip up with a remote control inside, as with past seats. The side-view picture made the bed look even skinnier than in your write-up.
apparently the bed in first class is about 28 inches wide
It does indeed seem to be too narrow. Hopefully the mattress is supportive and comfortable for sleep. I think the 1 seat + 1 bed is just too gimmicky. The JAL hard product is a much better option.
Honestly when they released the first renderings I thought it would have been smarter to convert both the bed and seat into a wider bed.
Or a Ying Yang Layout with a wider seat on the back and a wider bed on the front (you want to sleep in that direction in cruise anyway).
The narrow seat also means your likely to project food on the bed. I much prefer the Airfrance approach to have a living section and a sleeping lounging section and it would have been possible to make a similar concept work in that space though not as complex as AF did it.