The student aligns the bottom tray with the second leg.
text: Please rotate the shelf. Since that the foot you just assemble is on the table, and it's on its strip side.
text: Please keep the shelf vertical on the table. Just rotate it.
text: Please make sure your hands look good on the camera.
text: Please make sure the foot you just assemble is lying on the table.
text: Also please make sure the shelf is on the short side.
text: Please screwing the left foot on the top left.
text: Please make sure both of your hands are visible to the camera.