We have been hard at work releasing features and improving speed over the last few days. As a side effect of this, some safari users have reported that they are not able to see images when they drop them on the canvas.
This appears to be a browser cache issue. Issues like this can often happen on Safari after we release a new feature as Safari is loading a cached experience. Generally speaking, we recommend all of our Mac users to use Chrome as it is a better browser and handles cache much better.
For those that are experiencing these issues but would like to continue using Safari, we recommend using Safari private mode.
In the meantime, we are looking into ways to improve how our releases impact Safari users and hope to have this be a better experience in the future.