With a company that changes all the time, how can you show the personal touch of human interaction without showing pictures of humans? Essentially, blurring the line between technology and people, specifically as it pertains to customer service and advice.
Not sure what kind of product or service this is referring to, or what exactly you tested but sometimes hands can be more approachable than faces. Apple does a great job of adding the human factor to their tech in their commercials: http://www.youtube.com/watch?v=DCjeSNomXrU&feature=relmfu.
Also people are very sensitive to minor details in photos of other people. Things as small as pupil diameter can have a big effect on perception: http://westsidetoastmasters.com/resources/book_of_body_language/chap8.html. So before counting out photos of people in general because of your user-testing, you may want to look at the details of the specific photos. Cliche stock photo could also be a turn off: http://justcreative.com/2008/09/30/top-7-most-cliche-stock-images-used-in-web-design/
If people are definitely out, you could try obviously "lived in" spaces, like a kitchen with dishes still out or neighborhood street. (Apple does this as well.)
Picture of everyday use objects will do.
There are many elements to choose from, a few examples: