Use different settings for a Views' block basing on the content type of the node being shown I have 2 content types,  photo articles and video articles. On a photo article page, I want to have a block that shows 5 other photo articles. When I place this same block on a video page, it should show 5 video articles.

How can I use contextual filters to achieve this? I don't want to install a separate module to achieve this.
You can use Entity Views Attachment to attach your view to those content types instead of using blocks. EVA will allow you to pass in the content type of the current article as a contextual filter.