Each page on your website needs content. A picture cannot work alone when it comes to page ranking. You should not fill the pages with redundant text but you should plan to write some clever content. Your page needs to have small but rich content with SEO keywords. Google will always prefer a page with quality writing over a page filled with unnecessary text.
The content should not be all about sales:
True, you must create a website that mentions and advertises your service. But a great SEO practice is to develop a content that has a variety of information on your web pages. For example, if you are a software development company, you should not just keep on advertising app development. Instead, write some informative content related to technology, about your company, etc. Your uniqueness and the useful information relevant to your industry is surely taken into account by Google.