It is not possible to create a link on an image unless you put some text next to the image and select both text and image and then create a link.
After that, the text may be deleted.
This is not a very convenient workaround though.
This functionality isn't related to Dolphin it's in TinyMCE plugin which have such limitations, we'll try to update this plugin in the future in hope that this problem will be fixed there in newer versions.
It is not possible to create a link on an image unless you put some text next to the image and select both text and image and then create a link. After that, the text may be deleted. This is not a very convenient workaround though.
This functionality isn't related to Dolphin it's in TinyMCE plugin which have such limitations, we'll try to update this plugin in the future in hope that this problem will be fixed there in newer versions.