Import
From Synfig Studio :: Documentation
Pops up the Import Dialog. The images are imported with its dimension unless you have "<ToolBox> → <Setup> → <Misc.> → Scale New imported images to fit canvas" checked. Depending on what type of file you select, you can import images, videos (through pipe ffmpeg), SVG files, List Importer (.lst) files, etc.
See also other import scripts and options: