This is proof that you've reached the maximum Blast Gauge of 9. You can increase your BG using the Stack 3 bonus skill "Blasst". Coordinate your equipment just right, and you can blast off to new heights.
This is proof that you've equipped items that activate a Group Union bonus skill. Each basic skill group has a skill corresponding to each of the five elements. It doesn't matter where on your equipment you have the skills equipped; just equip all five skills in a group to form a Group Union!