If it still doesn't update, check the file size (buddy icons must be smaller than 4kb) and the image size (it should be 48x48 or 50x50 in most cases). AOL has set a limit for the maximum number of people you can have in your buddy list. If you don't think you are anywhere near that limit, it is possible that your server-stored buddy list is corrupt.
Buddy icons are checked when you IM people, so that may work. If all of that checks out and it still doesn't work, try restarting Pidgin.
ICQ was the first stand-alone instant messenger and the first online instant messenger service as such — while real-time chat was not in itself new to the internet (IRC being the most common platform at the time), the concept of a fully centralized service with individual user accounts focused on one-on-one conversations set the blueprint for later instant messaging services like AIM, and its influence is seen in modern social media applications.
At its peak around 2001, ICQ had more than 100 million accounts registered.
Pidgin will try to resize and convert the icon as needed to fit within the constraints of a given protocol.
Sometimes this fails and shows you an error message.
ICQ has no comprehension of character sets or encodings.
This means you won't be able to take advantage of certain account features, such as requesting your Tweet archive or taking advantage of security features like login verification.
In a world where we rely on e-mail as a quick and effective way to communicate and where we are developing the notion of “Going Green” to save our environment, we are asking that all parents who have e-mail capability to update our files with current e-mail addresses.
Note: Each time the email address associated with your Twitter account is updated, we will send an email notification to the previously-used email address alerting you of this change.
For more information on these types of alerts, read our Account security tips article.