Not extra shares /units .
But you will get extra value added to your account.
Let's say you have 1 unit and the accumulated amount is 0.012 $ .
Now let's say you upvoted 0.01$ to their post.
When the post payouts , 0.0134 $ will be added to your existing 0.012$ .
Which becomes 0.0254 $ .
Which will be upvoted to your post..
Hope you understood