Clipping Masks with Irregular Blob Like Shapes - Is it possible?

Site URL: https://www.sheisfree.com/blog

Hi Everyone, I'm working on a blog for a website right now and I've attached part of the XD Mock-Up for reference.

In the WIP blog page, I currently have the images clipped into a circle and using shadows to create the taupe outer shapes. But I would love to transform the clipping mask into a more irregular organic shape like the mockup. I'm not sure if that shape is achievable. I want to save my client the headache of having to photoshop the images into these shapes every time they want to post a blog and also eliminate any user error on their end, since they're not photoshop savvy. 

I was going to try masking the image over an SVG shape, but cannot find a way to upload an SVG file to Squarespace. I don't think that's possible. 

I've looked into https://bennettfeely.com/clippy/ but those shapes are more generic. 

I also found this article which I thought would be helpful, but still can't figure it out. 

Has anyone ever done this and have any insight? Thanks so much!