Some differences one might see in "higher" Episcopal services, are rituals followed in the services, such as singing certain parts of the liturgy, the priests burning incense, members of the congregation crossing themselves more often, and kneeling in reverence (genuflecting), the congregation generally kneels more often within a "high" service, and there might be slight differences within as well as frequency of the celebration of Holy Communion. The Holy Bible is read aloud, in both "low" and "high" services in the Episcopal Church. I have noticed more political commentary during sermons within a "lower" Episcopal service.
The above are also just my observations as a member since birth.
I have never heard a comparison between denominations such as Baptist and Episcopalian, or Pentecostal and Episcopalian, (as referenced in a post above) which would define differences between high church vs. low church.
It has always been my thought that the differences between "high" and "low" churches were found within each denomination, and not found by comparing one denomination to another. I have attended many Baptist, Methodist, Lutheran and Presbyterian church services with friends. I noticed many differences between services within each unique denomination.