Currently Being ModeratedNov 13, 2013 11:19 AM (in response to Liza Elena)
With Buddy List.
In Messages > Preferences > Accounts enable th Bonjour one if you have no other accounts other than iMessages.
In the Window Menu display the "Buddies" option.
Double click the current pic to reveal the change panel.
It should open on Recents, showing you the current choice and any other pic that has been used in System Preferences > User and Groups > you account > Picture, and the Contacts App > My Card > your pic. (you can set all three to be different but in Mavericks they have Common Recents Folder.)
The Panel should also show your Defaults (all the Pics that can be chosen for the Mac User Account Login pic and the "iChat Icons")
The iCloud (previously PhotoStream).
Faces (although the link to iPhoto does not work)
Linked (those used in the Login Pic and Contacts > My Card pic.)
Messages Menu > Change my Picture
This does not have the Faces, Linked or the iCloud one but does have "Other" instead which can navigate to any where on the Hard Drive but starts at "Pictures".
Example Pic with the Menu, it's Panel and the Buddy List drop down
Method 2 does not seem to work so well when you only have an iMessage Account Logged in.
This may be because the process was the Menu Method from iChat and not all menu items work with all windows that are open or all parts of the App.
iMac 2.5Ghz 5i 2011 (Mavericks 10.9)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.6.8),
Couple of iPhones and an iPad
Currently Being ModeratedNov 13, 2013 12:30 PM (in response to Liza Elena)