Changing size of Footer picture, Mobile version only

Site URL: https://accordion-jaguar-tztz.squarespace.com/config/

Hi, 

@tuanphan kindly gave me the coding to customize the size of pictures on certain sections of my page, which worked great. This was the coding;

Quote

1. /* Mobile Trailer Music Logo */
2. @media screen and (max-width:767px) {
3. div#block-yui_3_17_2_1_1651801243469_12688, div#block-yui_3_17_2_1_1651834325712_11700, div#block-b33f8ba5450f221ccfd1 {
4.     width: 50%;
5.     margin: 0 auto;
6. }}

It looks like this;

I would like to do the same, but with the logo picture I have on the Footer, but again - only on the Mobile version.

At the moment, the Desktop version of the Footer looks fine, like this;

But the Mobile version looks like this, I'd like to make it a lot smaller;

I'm guessing it's a similar coding to Tuanphan's, could someone help me write that CSS, so that it affects that picture all across the website, but on the Mobile version only?

The password for my site: ost

Thanks so much for your help!

Tomm