You can upload files from Box to use on landing pages and emails.
Go to Design Studio.
Go to Images and Files. Click File Actions and select Grab Images from Web.
Enter your Box login.
Allow Marketo to access your Box account.
Choose where you want to save the files. Then select the Box folder you want to upload from. Click Next.
Select the files you want to upload. Click Import.
Your files are now ready to be used on your landing pages and emails!