Transferring files from iMac to MBPro

I have older iMac and MBPro and want to transfer files from my iMac to my MBPro.  I have tried connecting the two by cable and using the MBPro as target mode.  However, a disk icon does not appear on the desktop of the iMac and indicated that should be the case in "Help".

I would appreciate your help and suggestions.

Thanks.

--
Vernon