Pinyin "ying" has an "o" sound? Look at 1:54 and 5:22 of this video: Chinese Pinyin in 6 Mins

Is ying really pronounced with an "o" sound?  This seems counterintuitive, especially when yin (at 1:49 in the video) sounds as a native English speaker would expect.
In IPA transcriptions of Chinese, ying is usually written as: [iŋ]. This is exactly like yin, except with an "ng" sound. However, as you noticed, some people pronounce it a little differently. This paper (page 9) transcribes the alternate pronunciation as [iɘŋ]. Wouldn't really call it an "o" sound, but the vowel is different than that of the yin.