The issue in part is because the images are very short and wide.
If you were to add some color to the tops and bottoms of the images to get their aspect ratios closer to 16:9 or 4:3 it would look better on desktop.
This might help a little on mobile but you might have to create another gallery where the images are tall and narrow.
Then with CSS show/hide the gallery blocks based on desktop or mobile. This technique has been discussed many times on this form but perhaps not specifically for gallery blocks.
emmachobson reacted to creedon in Remove block borders, help!
