The poll discusses the margin of error:
The survey’s margin of error is plus or minus 4 percentage points at a 95 percent confidence level. This means that 95 times out of 100, if a response to a given question to which all respondents answered was 50%, we could be 95% confident that the true percentage would fall within +/-4% of this percentage - or between 46% and 54%. As 12% of respondents in this survey answered “yes” when asked if they were a member of the LGBT community, we can infer that the sampling error specific to that response is +/- 2.4% or between 9.6% and 14.4%.The poll's methodology of asking the question "Are you a member of the lesbian, gay, bisexual, and transgender community, also known as the LGBT community?" online may be an explanation for why they received such larger values than the more typical 2-4% number that we have been more used to.