I didn't find one, so let me give the shareable link instructions a try...
Go to the regular page the Ancestry image is on.
On the right side of the image you'll see a little icon that looks like a wrench and hammer crossed. Click on that.
Go down to "Share" and click on that. Choose one of the social media for which you have an account and click on that.
A box will pop up. As soon as it fully loads, click on the x to close it. Another little box will appear with a link. Copy that link.
Come back to your profile. What you do next depends a little bit on whether you are using inline citations. I'm assuming you are. So, at the end of your Ancestry citation, skip a space and type a [. Immediate after that paste the link you copied from Ancestry. You can now erase the end of that link back to the first ampersand. For example, you can shorten
skip one space and type a description of what the link goes to. It can be as simple as the words "Shareable Image" (quotes not required) or more descriptive. At the end of your description, type a ].
Now you've provided a link to an image everyone can view whether they have an Ancestry subscription or not.
I have Ancestry source citations on this profile. A couple have no images and are records only, but at least one does have a link to image to which I provided a shareable link. I do not mind at all if you look at this in edit mode. I may not put every element in the correct order (I know some do it differently), but I think I have enough info someone could find the source there or in another repository if the link fails.