Unfortunately, it appears she was actually using the gesture to communicate to studio technicians who were trying to get her to mess up her lines. Thinking she was off-camera as footage was being run over her voice, she was a split second too soon and appeared to communicate sentiment shared with about 40% of Americans.
It appears this situation is a lose/lose for Limanova. By not flipping Obama the finger, she lost the support of a lot of Americans. By flipping the finger right after saying Obama's name, she lost the support of her employer.
Via the Telegraph:
Sources close to the channel had previously tried to defuse the row by claiming that the newsreader had believed she was off camera at the time and merely providing a voice-over for a report. She had raised her middle finger as a jokey retort to studio technicians who had been trying to put her off her stride, they said.Here is the video.