First thing as Scott suggested, RTE for text editor. you should use different component for image.
or you can have RTE and then give parsys. so that image component can be added there.
see how we have used parsys here:
https://helpx.adobe.com/experience-manager/using/htl_image_text.html
however previously in classic UI it was there. if you still want to use it.
please use below property in you RTE component.
useFixedInlineToolbar="{Boolean}true"
sling:resourceType="cq/gui/components/authoring/dialog/richtext"
~ Prince