Magento Marketplace delivers Extensions, Themes and corresponding Dependancy Packs in 3 separate locations, as you can see in the picture below.
Extensions Tab - containing purchased extensions
Themes Tab - contains purchased themes
Packages - contains dependancy packs for purchased themes and extensions that are mandatory to be installed for a successful installation.
Installation instructions for Marketplace Users:
Step 1. Download Pearl Theme files (Themes Tab) including corresponding dependancy packs (Packages Tab) . Pearl Theme is dependant of multiple dependancy packs that can be found under Packages Tab. Make sure to download all of them.
Step 2. Decompress and copy Theme Files at location 'html/app/design/frontend/Pearl/weltpixel' ; make sure to create the missing directories like ‘Pearl’ or 'weltpixel' respecting the exact upper and lower case. Do not copy dependancy pack files at this location.
Step 3. Decompress and copy dependancy pack files under '/html/app/code/WeltPixel/'; make sure to create the missing directories like 'code' or 'WeltPixel' respecting the exact upper and lower case for each dependency pack as you can see in below example: 'Backend', 'CategoryPage', 'CustomHeader' etc.. At the end you should have dependancy packs in your magento installation under the following urls:
Step 3. From this point you should be able to follow official Pearl Theme Documentation.