Toolbox
data + content blocks▾Data Extensions
▾Content block library
Click or drag a block into your email.
▾Assets
Sample images you can use without SFMC, or upload your own. Click one to view it and copy its URL - then paste the URL into an img src, or set it as a variable and print it.
Uploads stay in your browser for this session only and work in the preview, share card and download.