The file manager is a repository of your images and files that are stored and shareable across all of your Blasts and Interactions.
You can initiate the file manager by clicking 'Change Image' in the settings menu of an image content block.
Once launched, it will display all of your stored images. If you have large amounts of images you will be using, you can use folders to manage your images and you can also use the search function to find a specific image.
Click 'Insert' on the image you would like to use and it will be instantly loaded into your email.