tomasgf

I believe I actually found a way, by re-typing the code I was able to read on your screenshot above and targeting the specific block, which I understand is what you imply when you say "We can tweak it to run on specific summary".
That way other summary blocks that have the "wall" layout are not affected.
So, the grids with flex-end alignment look definitely cleaner, to my taste at least.
It's a bit time-consuming to have to target every block but in the end is worth it. The function should be of course native. Funny that it's not, isn't it? 
This is the exact code I used:
https://gallery.obra.se/alexander-skats
#block-642ebc4004d00e6ca9727cf2{
.summary-thumbnail-container  {     
  height: 406px !important; 
  display: flex;
  align-items: flex-end;
  align-content: flex-start; 
}}
So, I believe it works kind of ok right now, thanks to you Tuan, still curious about that 406px height!
In any case: It would be interesting to also achieve centred aligned thumbnails while having the text content aligned to its neighbours.
This aesthetic comes from exhibiting fine art in real life, therefore the interest in reproducing that same feeling of order for the artworks on view.
Other examples where in which I targeted specific summaries with above mentioned code:
https://gallery.obra.se/finn-anton 
https://gallery.obra.se/the-weather
 All the best,
Tomás