Whats the difference between befriending Pokemon with a heart and befriending without a heart in the Dream World?

Im pretty sure the question is confusing, so what I mean is what is the difference between a Pokemon who you played a mini-game with and got a heart then one of the ones you dont get a heart with. Let me explain more, lets say I enter the Forest area. I find a Ponyta and I play the Sky Race minigame with it. After the game is over and I have one the Ponyta shows a little heart above its head. What if I find another Ponyta and this time I dont get the heart over its head. Whats the difference?

Pleaselog inorregisterto add a comment.

The more Dream Points that are accumulated in a single play session, the happier the dreaming Pokémon will become. This is reflected in the icons which appear above the Pokémon when it is hovered over with the mouse.

Source

If you manage to accumulate over 500 Dream Points in one dream state of the Pokémon, it will raise a level upon your next Game Sync.- Serebii

According tothis linkthat means every time you gain over 500 dream points before your Pokemon is sent back to the game card, your Pokemon levels up.

It’s possible that it will have more happiness when you receive it in your game when it has a heart and I think it depends on how well you did in the mini-game.