I think it's about someone who lives in a city and misses someone they were with and who has left them for whatever reason, so now they fell lonely.
"Looking out the window
At another window
I see toenails changing colours
Like the leaves of fall"
This indicates they live in a city - instead of seeing trees changing colours, they see other houses and people who paint their toenails different colurs now and then.
I think it's about someone who lives in a city and misses someone they were with and who has left them for whatever reason, so now they fell lonely.
"Looking out the window At another window I see toenails changing colours Like the leaves of fall" This indicates they live in a city - instead of seeing trees changing colours, they see other houses and people who paint their toenails different colurs now and then.