I think this image represents a very important concept that we can see in the play "Waiting for Godot" by Samuel Beckett: TIME.
There is the tree that is described as one of the few elements that constitute the scenery, and some clocks that hang from it and represent the idea of time. In the poem, between the first and the second act, 24 hours have passed. However, the characters feel that ages have passed and that they are not the same person that existed one day ago.
Estragon is too stupid and superficial to understand anything. Vladimir, on the other hand, is an intellectual that tends to rationalize everything, so especially for him, time is related to crisis since his experiences are in a different tune in comparison to time. Vladimir notices all the changes that have affected the characters in just one day and he cannot endure not understanding what happened. If time is out of his reach, then what does he know about life? How can he be sure about his own life if he has no idea of how time has passed? Our society is a Vladimir-like society: we have to rationalize everything in order to understand everything, because if we don't, then nothing makes sense. Becket proposes the opposite idea: there is no point in trying to make sense and understand the universe because the universe is senseless. Even the simplest clock is senseless, because the seconds, minutes and hours that it indicates do not reflect the tiime that has actually passed.
At the end, for Becket, Vladimir is stupider than Estragon because he makes an effort in trying to understand the world when in fact the world is understandable and absurd. Estragon does not attempt at giving sense to the universe because he doesn't care about that: That's Beckett's idea of the universe.
Besides the idea of time, in the image we can also relate the tree with life. For Beckett, life is a cycle. If we think about the tree, the tree is constantly losing and growing leaves, and this marks the season in which the tree is. In our life we also have moments that define the "season" in which we are, the stages through which we advance in life, but at the end it's just a cycle and we go back to the beginning without even noticing. If life is a cycle, is there any use in trying to find its beginning and its end?
I believe that by looking at this image we can see the most important concepts implied in the play, LIFE as a cycle and TIME as unmeasurable, represented by the tree and the clocks.