Use the File Explorer to navigate to the folder you want to change icon sizes in. Using the top toolbar, click "View." You'll find a variety of size and ordering options for the files in the folder.

Copied Finder icons in Preview for PDF, an alias to a text file, and an image for an app. For some file types (such as PDF and other documents) doing this doesn't create a file icon, but a ...

Editable file types appear with a text file icon when you browse your Dropbox, and they're opened immediately with a tap. When you're done editing, tap Save, ...