Simple, minimal, stylish, artistic colours, good photography...
BUT... I gather it's meant for mobiles only, not 34 inch ultrawide desktop monitors! It's a common problem as more designers forget to cater for the larger end of responsive. Everything scales up to super jumbo size on large displays.
For example on your /gallery index page, you have 4 categories, but only 3 are visible on my screen, even when I have more than 80 cm of physical horizontal screen space available I still need to horizontally scroll to see the 4th category. That's a "mobile first, desktop never" approach.