In which scenario is a client service mashup used?

A client service mashup is primarily used for fetching and displaying data directly from the browser because it integrates various web services or APIs to create a unified interface. This allows users to see real-time data from multiple sources without needing to navigate away from a single web page. The mashup provides a more interactive and dynamic user experience by pulling in data from external services, which can include anything from social media feeds to live data from different applications.

The other scenarios do not align with the typical use case for client service mashups. For instance, embedding live data into a PDF document would typically require a different approach to ensure that the data is correctly formatted and embedded within the document for printing or sharing. Displaying static images on a web page does not involve any dynamic integration of data or live services, as it merely shows existing files. Lastly, creating a native application for iOS devices would involve mobile application development practices rather than using a mashup to pull data from various sources.