Leo crushes an apple, and examines its contents. nothing of interest. He eats the apple, setting aside the seeds and stem in a small pile.
He opens the jug of water, setting aside the cap, and pours some water into his customized idento-cup. (expospeakiness is next to godliness)
His hunger and thirst satisfied, he proceeds to examine the box. It resembles the "aperture science weighted storage cube" from Portal, though it is only a foot and a half wide (and long and tall, it is, in fact, a cube.) About four fifths from the top of the box, it opened, secured on one side by a small hinge in the middle. One corner is slightly dented from Rarborman's experimental toss. Leo is reminded that she still hadn't answered his question. it doesn't seem like the inside, which is composed of smooth metal, hides any secret compartments, although he thinks that the box's walls are hollow, judging by the weight. A quick tap on the floor confirms this.
He rubs a spot on the wall with a mattress, and the wet, slippery paint is found to conceal a "regular" black paint. The paint is smooth and glossy, and has no unusual qualities.
Rarborman beats the sandwich with the box until it falls apart into two roughly equal halves, and she and Leo eat the sandwich.
(Now, if you want to do this same routine every day with the food, you can just say so, and it will count as one action, or if you want to do something different, specify the change. [If you do change it, it will still count as one action unless do change it drastically) It's up to you.)