Passives used in differential signal lines
There is a big difference here. The top picture is a cable driver, cable and differential receiver. The bottom picture is a circuit that is used to differentially drive a local ADC.

The first scenario doesn't need to use capacitors to couple data to the twisted pair but, because it does, you could argue that the DC levels on the "send" end might not always match the required DC levels on the "receive end. In addition it can be firmly concluded that this type of data transmission is synchronous and different to RS232, RS485 or RS422 - those types of transmission are asynchronous AND dc connectivity MUST BE maintained because of the long periods of time that the line is idle.

The 2nd case (the ADC driver) is a very common circuit and is used as (or to supplement) an anti-alias filter.