After staring at the picture for maybe a minute, I hid the original and tried to see what I could come up in five to ten minutes. The result is... well, hideous, to say the least. My biggest problem was to get the actual number of people in the picture right. Since they all grouped in the left upper corner I drew some imaginary lines through their heads to connect them.
Analysis: The one figure I "thought" to remember well was the teacher, of whom I thought he was looking straight at the viewer. Totally wrong! He actually watches to the side. The three at the far end are above each other in a more or less straight line. The two persons on the left are actually on the same height and the two persons on the right of the line are somewhere in the space but definitively not where I drew them.