Here are the flex and margin settings I used:
The column: Display flex, then down the list: row, wrap, center, stretch, stretch. All the way from small to large.
The containers: Display flex, then column, no-wrap, center, center, stretch. At some larger breakpoint I adjusted it to
column, no-wrap, flex-start, center, flex-start.
The images: display block, width 100%, started 150px max-width, then increased to 250 and 320. It will be up to you how wide you want the images.
The title: display block, header 5, started at 14px font size, increased to 16px
Margins on the containers: 2px bottom margin at larger br.points
Margins on pictures: 5, 5, 15, 5 (top-right-bottom-left), increased to 10, 10, 15, 10.
Margins on titles: 8px (0.5 rem) bottom.