side by side content in a section for desktop vs. visual hierarchy of same content for mobile

Hi,

I am wondering how, structurally, I can take control and alter the visual hierarchy if a section is split with text on left and image on right... but when collapsed for mobile, default means all is stacked in a single column in that order. e.g. text appears first, then the image.

I would like to alter this so that the image winds up on top of the text and ensure it indeed pushes down the text (boundary box) so that the image does not wind up floating on top of the text.

Any reference or resources for this you can bring to my attn?

Thank you.