Hi Ryan, thanks for your reply, but it doesn't work yet.
For example:
I have 2 containers in my screen.
The first has my gif with an external URL.
The second one, with an image that I want to use as watermark.
This is my OnInitialize event:

My first step is convert a html block to binary data, so, I convert the image that I want to use as watermark. After that, I convert the image (binary data) to base64 and then, I'm trying to add watermark as you explain...
