Excuse my ignorance on the specific details of embedding images, however I am curious as to the reasoning behind the following scenario in the Groupwise 8 client.

I created a .png image file that is ~350kb and saved it locally to my machine. I sent this image as an attachment to my gmail account and the reported size was approximately 350kb, as expected.

When I use the "Insert Picture" from the Groupwise client to embed this image directly into the email, the reported size becomes ~850kb, almost 3 times the original size.

Finally, if I open the image file(using MS paint) and copy/paste it directly into the e-mail, the size becomes ~7200kb, over 20 times the original size.

Is there a fundamental concept of image embedding that I am not aware of? Why is there such a large size difference when embedding the image vs sending it as an attachment?

Thank you,