"V" Is Not Always For Vendetta

Riddle: It was during the autumn season of last year when Ruth began seeing a psychiatrist due to "hallucinations" she said she was experiencing. Ruth had lived her entire life in the city but had moved far out into a very rural suburb near a forest, and close to a small pond. She reported to her psychiatrist she imagined seeing a large letter "V" in the sky one day while walking outside, as well as hearing numerous high-pitched voices she felt were trying to communicate with her. After that day, nearly every time she took a stroll outside, she would see the letter "V" up in the air, accompanied by the voices. Sometimes she reported sighting up to five of these "V" letters with the distant voices calling to her, during her daily outside walks. The psychiatrist thought for a moment, and then told Ruth she wasn't experiencing any hallucinations, but rather, was seeing ....? What did the psychiatrist suggest Ruth had been observing?