Oh I know this!
Immigrants at Central Station 1951
By this poems strong use of imagery, demonstrates and illustrates the fear that surrounds the migrants.
"Like cattle bought for slaughter", which gives a strong allude to the genocide the Nazis inflicted on the Jews by way of the Holocaust, and this is an indication of the common emotion which is shared by the migrants - fear.
"Like a word of command" strongly relates to the traumatizing concentration camps set up by the Nazis at the beginning of World War Two. As such, this then makes the tone depressive as it conveys feelings of entrapment, anxiety and fear.
Josh