Neudesic Pulse attempts to cache as much information as possible for increased server performance. The result in certain scenarios is images not being updated on activity streams. To resolve this you must clear your browser cache. To do this in IE9 perform the following steps:
Open the IE9 “Internet Options”
In the Browsing History section click the Settings button.
Click the View Files button.
Select all the files in that window and delete them.
Click Ok, OK, then refresh the page.