The amount of RF energy that is absorbed (deposited into) human body tissue and the rate at which the energy decreases with the depth of penetration depends on both the type of tissue that the energy passes through and on the frequency of the incident radiation. Radio frequencies below 4 MHz the body is essentially transparent to the energy. As the frequency is increased more energy is absorbed by the human body. At high frequencies (around 1 GHz or more) there is scattering. Increasing the frequency of electromagnetic energy still further the point is reached when the body reflects radiation (visible light).
When radiofrequency waves enter the human body a portion of the energy is absorbed and causes molecules in the body to vibrate. On a macroscopic level these vibrations are what we experience and measure as heat (NIOSH 1987):
if you google human body absorption radio wave you'll find hundreds of web site talking about the topic... http://www.sgha.net/radiation.html
given that the SA6 use the 2,x Ghz band it explains why it has more issue with human bodies than old crappy 400Mhz or 800Mhz wireless headphone.
Depending on how you look at the bottle, either sleek could have made it more power full, other they chose to play on the safe side.