Centre (Front, holding microphone): This is Kaoru Mitsumune. At the time, she was a very high-profile trainee (13th generation) known for her distinctive short hair and "androgynous" model-like look. She was heavily pushed as a future star before her graduation later that year.
Right of Centre (Front, pointing): This is Karen Iwata. She was a member of Team 4 and was one of the younger, rising stars in 2012. Given the angle and her distinctive, energetic expression, she is often the one people misidentify as a later member.
Far Right (Edge of the photo): The girl you mentioned who is also pointing (partially obscured) appears to be Juri Takahashi. She was also a 12th-generation member and a key part of this specific "young" lineup for the Beijing performance.
Behind Kaoru (to the left): The girl with the ponytail and the hand to her mouth is Ryoka Oshima (13th generation).
Far Left: This is Miyuu Omori (12th generation).
Context of the Performance
This specific group was nicknamed the "Beijing Selection." Because the top "Kami 7" members were busy with the upcoming Tokyo Dome concerts and Atsuko Maeda's graduation (which happened only 6 days after this photo was taken), management sent a group of promising juniors to represent AKB48 in China.
They performed "Heavy Rotation" and "Aitakatta", and they actually won the award for "Asia's Most Popular Group" that night.
The "Beijing Selection" Lineup (2012)
Kaoru Mitsumune (Center)
Karen Iwata (The girl pointing in the front right of your photo)
Juri Takahashi (The girl on the far right edge of your photo)
Ryoka Oshima
Miyuu Omori
Yukari Sasaki
Tomu Muto
Mariya Suzuki
Rina Hirata
Nana Okada (Not to be confused with the later 14th-gen star; this refers to the 13th-gen Nana Okada)