[Evolution] Attachment Icons

[Jonathan Ryshpan <jonrysh pacbell net>]

In the message list there are two icons indicating that a message has an attachment: one looks like a paper clip the other like a power ball (or whatever).  They have different sort orders; the power balls sorts higher -- lower down in a low to high sort as shown below, which shows 3 paper clips above and 3 power balls below.  Questions:

1. What is the "power ball" supposed to be a picture of?
2. Which attachments are represented by paper clips, which by power balls?

Thanks - jon