Immersion theme: the header image is bigger in homepage than in other pages

Describe the issue or problem
Hi, one of our journals chosed the Immersion theme but noticed that the header page is bigger in homepage than in other pages. The journal would like to have the header image the same size in all pages, so we tried to understand how the different size is obtained, but with no result.
Can anyone, maybe @Vitaliy, tell us how this feature is obtained?

Steps I took leading up to the issue
The image different size between the journal home page and the other pages can be verified on the demo ojs of the theme

What application are you using?
For example, OJS 3.3.0-13

Additional information