This is a bad move using Scandavian

Quoting from R. Fines The Ideas Behind the Chess Openings:

"Black's basic idea here [in the Scandinavian] is unusual: he wishes to get freedom for his pieces at the cost of a theoretically inferior pawn structure and (on occassion) loss of time, in the hope that good development will make it possible to get adequate compensation, either in the form of a counter-attack or of a neutralization of White's powerful centre pawn. There is, however, only one line where compensation is theoretically sufficient and even there Black's game is extremely cramped. The defence cannot be recommended."

 I played the Scandinavian a lot when i started playing chess, because it seemed like such a straightforward and easy opening. However, after playing it a while, I started to grow tired of it. I had very little success with it, and all the players i faced seemed to have a breeze playing against the Scandinavian. It has never enjoyed widespread popularity among top-flight chess players, although some GMs play it on occassion. It is certainly playable, although it's not among the best responses to 1. e4.

 

Some examples:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Here is the diagram

 of the Scandinavian, can someone please tell me the main point behind this??

 

 

P.S this is my first time making a diagram

 

 

maybe you should post a diagram of it.