Neenor-
Google does quite a bit of work to keep pages that show "explicit" content from appearing, unless the end user is searching for adult content. Lingerie images walk a fine line between safe content and one that won't show up during a normal search. Based on what you've written, sounds like their site is more on the risque side of things...
The best way to see if your clients' site is affected is to turn Safe Search ON, and then see if their site will appear in search results.
Safe Search, according to Wikipedia (http://en.wikipedia.org/wiki/SafeSearch), is a feature that acts as an automated filter of pornography and potentially offensive content.
In a statement given to The Verge, a Google spokesperson said:
"We are not censoring any adult content, and want to show users exactly what they are looking for -- but we aim not to show sexually-explicit results unless a user is specifically searching for them. We use algorithms to select the most relevant results for a given query. If you're looking for adult content, you can find it without having to change the default setting -- you just may need to be more explicit in your query if your search terms are potentially ambiguous. The image search settings now work the same way as in web search."