If you want a non rectangle as the image, then you need to make a custom part (which is quite complex.) It will probably be easiest if you upload your svg here (upload is 7th icon from the left in the reply menu) making sure the svg is dimensioned in “in” or “mm” (not px!) so the scale is real world, and I will make you a custom part. You should also indicate where you would like the connection to the part to be in the svg (it defaults to the center which likely isn’t where you want it.) It is easy for me, likely less so for you if you are new to part making. This tutorial will tell you what I am going to do (and usually discourages people from making parts 
):
there are 11 or 12 parts to it.
Peter