NostrGram does get pretty close to that if you click the Pinterest icon under the Note Editor at the top of the page. The difference is it has more spacing between images and shows user details -- but it removes all the text from the notes so it's just the media. That's pretty darn cool though.
Discussion
It's very close indeed!
Now that you've given me the idea I'm working on an even more minimal display that gets really close to that. Give me a few minutes!
How's this? 
#[2]
Add infinite scroll and/or a "Load more" button and it's basically done! 👌
NostrGram infinite scrolls by default so you're good there. Made one last update to it to remove the author header (you can click on the image to get all those details). 
Awesome! Infinite scroll doesn't work for me in Firefox, but it might be a me problem. Will try again tomorrow with a different browser and/or set of extensions.
Keep up the great work! 💪🔥