Hi Guillem,
Unfortunately, we only support HelpText/Tooltips for the text portion of the node. However, it is possible to use Syncfusion.Windows.Forms.ToolTipAdv along with the MouseHover event to implement your own tooltips. I have created a
sample that demonstrates this. It uses the PointToNode method to find the node that the mouse is hovering over.
Please note that this sample displays the tooltip over the text and the image. In order to limit the tooltip to the image you would need to implement custom detection based on the node size, node state, etc.
I hope this helps and please let me know if you require any more assistance with this issue.
Regards,
Gregory Austin
Syncfusion, Inc.