There is a guide available for the system migraiton tool here http://support.lenovo.com/en_US/detail.page?LegacyDocID=MIGR-50889. The guide contains a number of variables specific to UMA that can be used. UMA also supports environmental variables. The problem you are running into is that in windows 7, the pictures directory is a library, not a folder. The library may point to multiple picture locations.
The variables you used %userprofile%\pictures does not point to a valid folder. The correct patch is %userprofile%\my pictures. Also, when you are using the %username% variable, are you putting a driver path on the beginning? If not, there is no way to find the correct path. Those variables and paths can be tested from start > run in windows to confirm that they open the directory you are trying to capture. %Personal Directory% is a UMA specific target and cannot be run the same way, but it points to the My Documents folder. In windows 7 the pictures directory exists above that folder level. Also make sure that you are not using %%, normally in provisioning local variables need %%, but the profile capture configuration is not using the provisioning variables so it does not need %%, only %.
Try using c:\users\%username%\my pictures or %userprofile%\ *.jpg (etc).