Then, this rotative piece is, in a side, a mirror and in the another, a lamp (hence the 1.5x2 batteries in the step 2).

To remove it, you need pull a side. The rest will come alone.

The picture is a little fuzzy but we can see:

The bulb.

The support of this rotative piece.

The battery.

The cover which prevents the bulb to fall.

The mirror and the bulb location