Now seen the shower first hand. The room is very large (probably 3 times the size of a normal toilet). Has toilet, oversized washbasin, floor to ceiling mirrors and of course the shower.
The shower cubicle has handles and a seat, in case a bit of CAT occurs while showering. Also has a crew call button and the 'get back to your seat' light. The oxy mask drop hatch is just outside the shower door.
The shower is controlled by a single push button (and a standard temperature control), so the flow can be paused whilst you soap up. This makes the 5 minutes very generous in fact. The lights are not a simple 'traffic light'... each zone is subdivided into 4 or five sections, so there is no excuse to have soap still on hair/body when the time runs out.
Very impressive - pity it's only available for 1st class pax. I was told by the crew that they take advice from the captain re expected turbulance and they will not allow shower use in that case. Both showers have a 30 minute 'appointment' slot, which needs to be booked via the purser.
By the way, the '90' figure quoted above is for the entire upper deck... 14 in first class and 76 in business class. There are (in this configuration) 399 economy pax downstairs.
Emirates will eventually run two other configs - a medium haul (also 3 class) with no crew rest area, giving room for more economy pax, and a short haul 2 class (no first class) for travel (say) from Dubai to Riyadh; where Emirates are constrained by number of slots, but can easily fill 600+ seats for that routing. Strange that they want to use such a huge beast for a 1hr flight, but they have done the maths on the economy.