How to designate the correct version of thumbnails in product categories?

Question

WordPress

On the pages of the catalogs and on the main page, products are displayed 5 pcs in a row and 2 pcs for the mobile version. The problem is that the final size of the images is much smaller than the thumbnails that are picked up when the page is generated. Those. in the mobile version, 600x600 thumbnails are loaded, although 150x150 would be enough there. In the PC version, 300x300 are loaded, although 150x150 would also be enough. All this leads to an unnecessary increase in page sizes.
Tell me how to explain to WordPress which thumbnails should be used on the category and main pages.
Google, I could not formulate the question.

Answer 1

Well, apparently there is some kind of hidden block that is shown on mobile phones and already in it, through the code, it is written what size of the thumbnail to display. Read here _