Mihoyo hasn't formally revealed more details yet about Yae Miko's attacks and abilities in Genshin Impact. However, leakers have released content into the wild, showcasing her attack animations, Elemental Skills and Elemental Bursts.
As seen on Areha's video, Yae Miko's attacks are from Catalyst, but doesn't rely upon it too much. Unlike other Catalyst users, Yae Miko falls back onto her own tools, such as her Gohei wand to call down electricity on her foes. The Catalyst is often left to the side.
Genshin Impact Leak Reveals Yae Miko Attacks, Elemental Bursts, and Other Animations
Furthemore, these leaks show that Yae Miko's Elemental Skill allows her to plant hairpins on the floor, setting up three linked with electricity. It's unknown if this electricity can damage foes, or whether it'll be a gateway to buff her allies.
Lastly, her Elemental Burst shows Yae Miko's tails and calls down thunder on her foes. We've yet to see if this move can heavily damage enemies or buff allies in the electric blast, similar to Kujou Sara.
Presently, only Yae Miko's poster teaser has been officially revealed for her playable version. Fans have yet to see her in action, as she mostly plays a non-combative and mysterious role when appearing in the story. We'll have to wait for more information from Mihoyo to see if this leak proves true.