Responsive image on left column (page header content)

Hi!
Header content of my home is a horizontal section divided into 2 columns. Left column has a image, and the right column has text and a Thrive Leads form. My problem is with the left column.

Image looks perfect on 13" screen, but it's "flying" in 20" or superior screens. Can you help me, please?
I think that the problem is the height of section, but I don't know how to remove it.

My code on Page Header > Content is something like this:

[lgc_column grid="40" tablet_grid="100" mobile_grid="100" class="imagehome"]<img src="URL.jpg" alt="Blabla"></img>[/lgc_column]
[lgc_column grid="60" tablet_grid="100" mobile_grid="100" last="true"]
<h2 class="home">Heading</h2>
<p class="suscripcion" style="margin-bottom:1em;">Paragraph
[thrive_leads id='1135']</p>
[/lgc_column]

P.D.: I cannot update GP Premium to 1.3. from WordPress dashboard :/