This is couch stitch and demonstrated by Wendy from shiny happy world dot com again.... I think she has a great manner and shows people how easy it is to embroider.... I am all for hand embroidery as you know and watching her demonstrations on how to are a great way to show you that it is not as difficult as you may think.
Couch stitch is great as you can use two different threads or maybe a ribbon if you wanted,
For a shape like a heart you can draw your heart on your linen and follow round couching and it has the most wonderful effect!