
Yes don't sympathise. do not pick up or pet him, or even talk too soothingly to the pup. If you do it will percive from your behaviour that there really is something to be scared of, or that the attention it gets for acting frightened witll get it lots of attention.
The best way to be is to speak in a cajoling don't be silly.jolly hockey sticks kind of voice, and encourqage the pup to walk on ignoring the mini monster. After it will do this another time just stop and chat to the little dogs owner ignoring the frightened behaviour. Often when the pup sees you interacting in a friendly manner with the other dogs owner it will become braver, not liking to be left out.
It is similar to a shy child, if you focus your attention on the shyness it makes them worse, but if you ignore it they will make friends once feeling more comfortable.