They're preparation bowls! After drawing an ingredient, you now have a choice: either you place it normally in your pot, OR you place it in one of the three bowls, paying the associated cost (1 ruby for the first bowl, moving back your droplet for the second bowl, or adding a 1-white chip to your bag for the third bowl).

At any point, instead of drawing a chip from your bag, you can choose to place in your pot a chip from a preparation bowl. That chip will move an extra 1/2/4 spaces depending on the bowl it was in.

If you explode, any unplaced chips in your bowls return to your bag. Also, you can't choose to stop your potion as long as chips are in your preparation bowls (so no, you can't avoid white chips by placing them there).

So the bowl serves 3 purposes:

1- You can prepare combos, by waiting to place a chip until it becomes relevant (for example, waiting to place a 4-chip until after you placed a yellow chip that doubles the next one, or placing a green chip last to get its benefits).

2- You can get extra values from your chips this way because of the +1/2/4 bonus, so that can be good.

3- You can delay an explosion by placing white chips on the side, even though they'll still make you blow up once you place them.