You don't need to see it from your friends' blackberry, you can do from your own Blackberry to see your own Blackberry messenger display picture.
Open the Blackberry Messenger.
(for version 5 OS)
Go to your display picture
Choose Enlarge Display Picture
See Also :
• How to open and unhide the hidden file/picture in Blackberry
• How to Hide Photo or Picture in Blackberry device
• 'Ghost' Picture Using your Blackberry Camera
• How To know The Version of Blackberry OS