What is the significance of the view from Gregor’s window?

In Franz Kafka’s Metamorphosis, protagonist Gregor Samsa famously wakes up as a giant beetle. On the first day that Gregor wakes up, he looks out the window and both sees the rain and hears it on the metal window ledge. He notices the dreary view from the window before he even notices his transformation. As he looks out the window, Gregor also thinks about how he fears his boss and hates his job. The metal fixture on the window represents the post-industrial age that Gregor inhabits and corresponds to the fact that he feels alienated and exploited at his job.
The view from the window is one which features a gray sky and gray earth, which is symbolic of Gregor’s pre-transformation disposition. After he becomes a beetle, Gregor notices that he can no longer look out the window with the same perspective (i.e., he cannot stand up). This suggests the uniquely tragic circumstance in which Gregor finds himself; he never particularly enjoyed the view outside, though now, as a beetle, Gregor is robbed even of this despondent view. Nevertheless, he continues to look out the window, which is symbolic as a means of escape (if only a mental escape).
Affirming the window’s symbolism as an escape is that Gregor’s family members flock to it at various points in the novel. In particular, Gregor’s mother runs to the window when she is in his room, despite the fact that it is cold out. Likewise, Gregor’s sister opens the window to prevent herself from feeling suffocated. Both are trying to cope with Gregor’s transformation, and the window is a crutch for them. The fact that Gregor only looks out of the window while the others open it symbolizes Gregor’s extreme level of entrapment. He is physically trapped and demoralized in his condition as a beetle.