Originally Posted by sehgalanuj

I think Ben has provided us info on how the blocked seat is intended to work, but in practice that's not how it works. When the blocked seat works correctly, for now, this is what happens:

• Somewhere in the 30-48hrs window before departure, if the seat next to you is empty, it will get blocked.
• The seat will show on the seatmap as greyed out. If you hover over the blocked seat, the message will read "Seat not available". If that message doesn't show, then the seat is occupied by another passenger.
• If you move your seat to another one, the blocked seat will remain where it was and your new neighboring seats will not get blocked automatically. The automation that blocks the neighboring seat runs only once during the departure control window, but any movements after that aren't accounted for.

The only way to check if the seat next to you is blocked, at least for now, is to hover over it and see if the "seat not available" message pops up.