SPOILERS! IF YOU WANT YOUR MINDS TO BE BLOWN, YOU MIGHT WANT TO SEE THE NEW STEVEN BOMB 4 TEASER FIRST!

In the teaser/trailer of Steven Bomb, we find out that it is Steven's Birth-Week and we find out that things will soon be going upside down. Nearing the end of the teaser, we find yellow diamonds forming in the sky. Surely, the mysterious Yellow Diamond is behind this. After that clip, the scene changes to Peridot where she seems happy that she can finally get off the planet. Then the scene changes again to Peridot attacking the Crystal Gems with her green robot.

Reverse to Peridot's face. Her gem was actually glowing yellow meaning that her gem is in use. That must mean that Peridot can use her gem. But why is Peridot using her gem at this very moment? I'll get to that later in this chapter because I need to explain the abilities Peridot's gem has.

All gems have a weapon (or shield) that they can summon using their gem. Peridot never used her gem for weaponry except for the device that deactivated her flux robonoids (which, we can say, is not exactly a valid weapon for a gem). We have no idea what Peridot's weapon is, but it could be some kind of ranged weapon since she was so good with it.

All gems also have one or more side abilities. For example, Steven has a bubble to go along with his shield plus healing spit. Pearl has Holo-Pearl with her staff. We know that Peridot has created a more realistic holographic-gem in Friend Ship, but there could be another ability she has not discovered yet. She could have the ability to create portals anywhere she wants, thus the yellow diamond portal-looking thing in the teaser.

Now to why Peridot's gem was glowing. Maybe in the episode where Yellow Diamond appears, the Crystal Gems were showing Peridot how to operate her gem much like how they taught Steven. Then this big yellow object appears in the sky and it is revealed that Peridot could create portals or that Yellow Diamond has came for Peridot.

We may not know for sure, but what we do know is that this will be one exciting episode (or cliffhanger).

EDIT: After another examination of the promo, it seems that Peridot's gem wasn't actually glowing. BUT NOTE that it was a short clip, so we may never know.