In Spark, click on the share button underneath the image you want to copy. Click on embed and a box with the html code will pop up. Highlight and copy.
Go to your muse sight. Click roughly where you want to put the video. Click on the menu Object/Insert Html
A box will pop up and paste the Spark HTML code in this and press Ok. It should whizz away for a few minutes depending on internet speed. Eventually, the Spark Image (icon) will appear. You can resize the box (to a limited extent) and reposition. Publish as normal.
When some clicks on the icon the spark page will open.
I have it working on my site. Look at the Blog page at phlap.com.au