意思意思 is a slang ,
something you don't do much for some reason, but it means a lot more than it looks.
for example: over dinner , somebody is allergic to alcohol. when it's time for toast, somebody just licks a little wine to moisturize his lips ,or drink tea instead of wine.... he will explain that "意思意思”-------means he can just drink a little, or drink a substitute for alcohol...but it means as much as alcohol. ( to Chinese people, toasts with alcohol means sincereness .)