Differences between TVS diode and Zener diodes, in diagrams and in practice?
The reason the same symbol is sometimes used for TVS diodes (Transorbs) and Zeners, is a Transorb has a lot in common with a Zener. An ideal Zener and an Ideal TVS-diode would be indistinguishable in their characteristics. 
This leads to ... laziness in library management (or ignorance) and the same symbol is used.

Regulator Zeners and TVS-Zener diodes differ in aspects of their construction to facilitate either higher continuous rating or high pulse capability. 

Zener TVS devices are constructed with large area silicon p-n junctions designed to operate in avalanche and handle much higher currents than their cousins, Zener voltage regulator diodes

Only uni-directional TVS diodes are created at wafer level.  The bidirectional TVS diodes you can buy are just two such dies packaged in series. 

Examples of symbols for some TVS devices:





From your images


Zener diode unless the part number calls up a TVS
TVS
TVS
Back-to-back Zeners unless the part number calls up two unidirectional TVS 


http://www.onsemi.com/pub_link/Collateral/HBD854-D.PDF

Using a TVS diode instead of, or in addition to a MOV for AC line protection?