In the screenshot the machine with IP address 10.142.1.1 is acting as both NameNode and DataNode
Namenode and Data node both are basically network services which are running as background processes. These services listen on different ports. Therefore, it is very much possible to have namenode and Data Node on the same machine. Though it might increase the load on the machine but it is okay because namenode process requires more memory while data node requires more disk storage and read/writes to the disk. So, both are kind of complimentary when it comes computing resources consumption.