Image Alignment Question

Now that I am on 2.6 and using the gallery and captions (which I love), I simply can not get my images to place next to each other in a post. Instead, they run down the page rather than appearing side-by-side.

You can see an example here, towards the middle of the page:

https://madisondining.com/talula-fills-the-niche/

Help is appreciated!