Thank you for your post.
At this time, this is intended, as it is a security and accuracy issue.
Keep in mind that WebDirect is not just HTML web pages that get displayed in the browser client. There are several components (browser, web server, database server, etc.), and to ensure optimization and security through all components, the image is downloaded each time.
I recommend posting to the Product Ideas board at: Product Ideas
The Product Ideas board is monitored by Product Management and Development. All entries are read, discussed and considered for possible implementation in a future release.
Thank you for your answer, I'll post it to the Product Ideas.