When I place a link on a form I can define it to open a form or a microflow. When you select microflow you can define the settings for the microflow.
But when I have an image I do have both options (open a form or a microflow), but the microflow settings are not there:
It seems strange to me that there is a difference between these two. When I use an image I should have the same options as I have when I place a link.
I created a question on the forum today with the same context. Maybe this will bump the feature request :)