Mobile images aren't re-sizing the way I would like

My website http://www.srspartnership.com is having problems with me resizing the slider images for mobile. I really like how http://www.brandelion.co.uk/ has done their header slider images. Especially on mobile. I cant seem to find the code to edit my header images effectively so any help is welcome.
Also how do I fix my mast head to be sized like brandelion for mobile? it fits perfectly.
cheers, Stephen

Hi Stephen,

You’d need to disable responsive header slider by going to Appearance > Customize > Header area > Header Slider. Then scroll down to the most bottom until you get an option that says “Slider mobile behavior”, enable Full screen, and then Save.

Regards,
Kharis