I have visited the nap rooms about a week ago, but didn't take a picture. They have 20 (!) of them and they're very similar to Yotel There's a couple of differences though:

KLM

• Minimum stay (=minimum pay, you can leave earlier) 3hrs
• Price 49,50 EUR
• Shower in adjacent shower cabins, so in case you'd like to shower after your nap, you'll have to walk out of your sleep cabin to the shower area and also make sure you reserve one or risk waiting a couple of minutes.
• Toilet in regular lounge facilities.
• Shower amenities include shower gel, toothbrush, shaving kit.

Yotel

• Minimum stay (=minimum pay, you can leave earlier) 4hrs
• Price 52 EUR
• Shower in the cabin.
• Toilet in the cabin
• Only shower gel.
• King beds available.

Both offer bunk bed style sleep cabins (but you'll have either the upper or the lower bed, as they're in different cabins). I don't now if KLM offers double beds or only single cabins.

I have absolutely no clue why KLM has chosen not to have shower or restroom facilities inside the sleep cabins...