Are you using the image control from the toolbox?
the Image source should be external.
The Expression should be something like.
="/Images/" + Fields!EmployeeID.Value + ".jpg"
The reference to the image cannot be a location on the hard drive, It needs to be a reference to the image in the same folder as the project, or on a web server.
Check out this link about referencing external images. There's probably tons of thers.
http://technet.microsoft.com/en-us/library/dd220423(v=sql.105).aspx