@JenniferLink1 -- Currently, content embedded in a story shows as a card on small screens, so this behavior is expected.
This is because most authors typically embed things like dashboards and mapping apps in their stories. There isn't room for these types of apps to be displayed inside a story in a small frame on small devices. The card is shown so readers can understand what the content is and, if they want to interact with it, they can tap it to open it in a new browser tab where they have more space.
However, we understand that some authors want to embed simpler pieces of content, so we have been considering an enhancement that should help in those cases where the embed would look and work fine on a smaller screen: we're looking at providing an option that would let you choose to show the live embed on small screens.
We don't currently have a date when this might be available, but it is on our list.
Owen Evans
Lead Product Engineer | StoryMaps