The UNCLE was an organization with many secretaries. They conduct research and established contact between the agents and the director Alexander Waverly. Occasionally they worked in bikini taking artificial sunbathing (when no one was looking).
This means that the UNCLE was a misogynist organization? We can not forget that the series was produced between 1964 and 1968. And the world was very different. In many offices the secretaries were treated as prostitutes. This became very clear in the series Mad Men, which portrayed the same period.
But the secretaries of UNCLE were not call girls. They had an active role in global security and pioneered the use of computers. Some of them became agents. Here are some shots of the UNCLE secretaries in the first 11 chapters: