I know this is past the time restraint mentioned but, just for future reference you can also:
run 'mc' file manager. Also known as 'old faithful', 'tried & true', 'mr wonderful', etc etc etc
Have both columns in same directory.
Highlight all required files in one column, then press F6 for rename/move and in 2nd line option ( the where to line) just put *.jpg. Done.
Not explained too eloquently, but seriously folks there is not a Linux install on the planet that should not have 'mc' file manager installed!!
Life isn't about waiting for the storm to pass...
it's about learning to dance in the rain.