[Permission Required: Account Admin, Content Admin]
The in-site search opener, when enabled, is found on the top right corner of the site.
Customizations for the in-site search opener can be done on the theme level, and so you might need to clone the theme first to prevent other sites from being modified. Please refer to this article about cloning a theme.
To change the size of the in-site search opener:
1. Go to the site editor of the site you want to the second logo for.
2. Click on Styling from left pane menu.
3. Click Edit Site CSS ... button under Local Site Styles.
4. You can scroll to the bottom of the CSS editor if it is not empty with other CSS snippet.
5. Insert / paste the italicized code below:
where XX refers to the numerical value for the width of in - site search opener, while YY refers to the numerical value for the height.
6. Click the green Publish button on the upper left of the editor.