Pictures play an important role on dating websites. That comes as no surprise. From our early childhood we learned to synchronize our parent’s facial expression with the content of their speech. And later on we were always sure that the one we observed was the one we talked to, that visual information and communication were in sync.
This is by far not true any more on a dating website. Depending on the rigor by which it is controlled, I guess that 20-80% of the picture are misleading or outright wrong. Therefore you cannot trust pictures. It is up to your cleverness to discover how the person you are talking to looks like. Facebook, for instance, is much better controlled as pictures are shared with friends who know each other personally.