I believe this scene indicates that Homura has become the "Law of the Universe" itself. While Madoka was represented by her "cosmic skirt," in Homura's case, it is her "cosmic face" (as seen in the new trailer).

In Rebellion, Homura became a "new concept of the universe." If we follow Gen Urobuchi's interviews, she is meant to be the "two sides of the same coin" to Madoka. Here is a summary of the official sources that support this:

The Two Concepts of the Universe

Ultimate Madoka

>""You'll be firmly implanted in this universe as a concept - a principle that destroys Witches." — Mami, Episode 12

Devil Homura:

>"The world is being rewritten... Has a new concept been born into this universe!?" — Kyubey, Rebellion Story

Urobuchi (Writer) on their relationship:

• "I decided to make Homura a being that exists as a pair to Madoka."
• "The plot solidified once I reached a conclusion where Madoka and Homura would become equals." — Rebellion Theatrical Pamphlet
• "Since I wrote a story about the birth of a God, if I follow it with a story about the birth of a Demon, they become two sides of the same coin." — Broadcast on 2013/12/22 at Nico Nico Douga

Supplement: Points where Homura holds the advantage

1. Resistance to the Kyubey

Ultimate Madoka:

• Kyubey: "Eventually, our research will completely overcome the 'Law of Cycles'." (Rebellion)
• Shinbo (Director): "Kyubey will eventually be able to capture the Law of Cycles. The story is structured that way." (Official Guidebook p.111)

Devil Homura:

• Kyubey: "Beyond [our] control." (Rebellion)
• Urobuchi: "A power that even defeats the aliens." (Official Guidebook p.111)

2. Source of Power: Other-Power (Karma) vs. Self-Power (Love)

Ultimate Madoka (Other-Power / Karma):

• Kyubey:** "You see, a magical girl's latent potential is based on the weight of the karmic destiny she bears." (Episode 11)
• Urobuchi: "It was to Homura's credit that because she went through time loops many times and bound up the causalities so that Madoka possessed the power strong enough to bend and twist the law of causality." (Shinjidai no Mixture Magazine BLACK PAST)
• Madoka:** "Now, grant my wish, Incubator!" (Episode 12)

Devil Homura (Self-Power / Love):

• Official Guidebook (p.69): "After cutting apart a godlike being through the power of love, Homura names herself a devil.”
• Urobuchi: "She herself possesses a power that can even wound a God." (Broadcast on 2013/12/22 at Nico Nico Douga)