Rehub theme is multipurpose theme, this is why we added unique Product Layout templates. Each template has different look and has best fit to own purpose. For example, Full width photo layout is better for Booking products with big photos. Full width Extended is good when you have big photos of product with good quality. There are also some special Product layouts for Content Egg plugin and for Vendor Comparisons
Each product can have different product Layout. You can set them inside product edit page
Also, you can set global Product Layout. It will be in use if your Product has Default Global Layout. To set globally – choose it in theme option – shop setting
If you want to customize Layouts – all files are in inc/parts/product_layout folder