hotlinking. That has changed because the latest update to Google Sheets allows you to upload images to insert into cells in your spreadsheet.
This new feature is available now for some Google Sheets users and will be rolling out to other users over the next two weeks.
Applications for Education
This update probably won't mean much to most students. But for those students who do use Google Sheets to create data visualizations or to maintain databases that have a lot of visual components, this update could be helpful.