In order to change your default style and layout type within a shortcode, you can use parameters with the google reviews plugin for wordpress.
Example 1: create reviews widget with style preset #1 and grid layout:
[google-reviews style="1" type="grid"]Example 2: create reviews widget with style preset #8 and slider layout:
[google-reviews style="8" type="slider"]Example 3: show reviews badge layout:
[google-reviews type="badge"]
