First, a brief preface: This feature request is primarily for the PostEm tool, but it can also open a wider discussion on allowing instructors to customize the tool icon behind other "less" standardized tools in Sakai.
That said, the PostEm tool in Sakai currently allows instructors to post different types of feedback for students. Examples include: a) grades, b) attendance, c) comments, d) a combination of these, or d) any other creative use-cases not mentioned here. Given the latitude of how instructors can utilize this tool for courses, it ought to be possible for the instructor to select an alternative tool icon that reflects the way he/she is using it.
For example, perhaps an instructor wishes to use the PostEm tool as a way to post student grades. In this case, the instructor may wish to select a tool icon that matches this objective. The current icon – a folded post-it-note – does not necessarily communicate this purpose.
Currently, the "Web Content tool" allows instructors to customize the tool icon for their own purposes. This makes sense, given the different use cases that the Web Content tool supports. By extension, the proposal here is that the same ought to be true for the PostEm tool.