Structural Shift has many uses, too many to list in fact without requiring its own guide, but it is obviously the number one key to playing Svara well. It allows her to move structures into better positions and it puts enemy offensive units in bad spots. Often units use enemy gates to protect their advance, that is a key element of Summoner Wars strategy, and Svara cheats that entire system. Trying to do that often means Svara will just move the gate, removing the protection of that unit. This is the reason it is so hard to attack Svara.
Gates can be moved into offensive positions as well. One of the easiest, strong plays is moving the initial 10 life gate into a position that is uncomfortable for the opponent.
It also makes Parapets incredibly unfair, works with Ice Ram and pushes Ice Golems faster than they should normally be allowed to move. It is also often just used to "cheat" by creating turns with an extra movement (as an Ice Golem and Svara both move in the same movement).
And of course structures are moved to support the Frost Mages and reposition Parapets.