Whenever I think of assessing or creating a design is to repeatedly ask "why?" until the product or service is boiled down to its essence - minimum required "design" to make it functional. Then, the immediate priority should be to make such a design accessible - sufficient contrast, color palette, font size, column width, etc. Aesthetics that emerge from this kind of bottom up approach always in my view trumps superficial top-down design where a designer has some kind of a personal subjective vision of their aesthetics which is then used as a mold to engage in the design process - the latter usually results in a poor overall product or service. This is just a general pet-peeve of mine, not inclined to your work. :)
In this case, I used the Masronry.js library for the thumbnail grid, and the unnecessary animation you speak of is mostly the result of that. Basically, it reloads the grid after every thumbnail image is loaded, and the reason I stuck with it was to eliminate the visual lag of having no thumbnail grid at all while all of the images are loading up – but perhaps it should be the other way around?
This can easily be disabled in the template via the initGrid.js file. Perhaps I should document that option more thoroughly. :)
Thanks again for your feedback!
Edit: I've since updated the site to load the grid up after all images are loaded, eliminating the dancing animation.