Header question

this is a neeb question, but I haven't run a wordpress site in like a decade, so ….

I've got a frontpage I like and it has a focused image that takes up a lot of real estate. that looks good on the front page, but I don't want it on every page.

I tried to install the "conditionally hide focus image" plugin and it does remove the image, but there's still a huge grey box up where the image was. If I try to put a smaller image in there, it expands to fill that space. Not ideal.

Anyone know how I remove or shrink that header on pages that aren't my home page?