In that case, I assume you wouldn't have any problems as they (getstencil.com) is very likely picking the photos from the sites where those photos are free to use for commercial purposes and even doesn't require the attribution.

The only problem that remains is fake linking, as your Photo source links don't lead to the photo itself (as they should) by that giving the attribution to the author what is the main purpose of the photo source links.

From my point of view, if the photos that you get from getstencil.com are free to use and free to use for commercial purposes, and as well don't require attribution, it would be better to skip entirely the photo source link than providing a fake one (with entirely different purpose which is, in fact, your possible affiliate earning, if someone signs up to to getstencil.com through your link).

Meaning, getstencil.com is not the owner or the copyright holder of those images, but just a mediator who provides them (as they are anyway free to use) through their paying photo editing tool service.

In other words, and when you already mentioned canva.com, if you would find such free to use photos, images, illustrations, etc., which are free to use and don't require attribution through the sites like Pixabay.com, Pexels.com or similar (where from getstencil.com most likely put them in their database, anyway), and upload them to canva.com (which is the tool, as you said by yourself, very similar to getstencil.com, you would be able to manipulate and edit them almost the same way but without need to pay the monthly fee to getstencil.com either not to canva.com as you would be using free photos from one of the above-mentioned or similar sites. Think about it!

And I can easily prove you what I'm talking about with the very photo that you used in this article. Meaning, the photo could be easily found on the following Pixabay.com page and on the right side menu, you would see that it's licensed under CC0 Creative Commons license, free to use for commercial purposes and with no attribution required. You can easily download it from there and upload it to canva.com, play with it however you like and publish it on Steemit, all free of any charges.

Besides, that's why I told you in my previous comment that you wouldn't have a problem with this particular photo, as according to its license even the photo source link (attribution) is not required.

Personally, I attribute the author (although it's not mandatory) whenever I use the images from the sites such as Pixabay.com is, and which in this concrete case is someone who present him/herself with the nickname yourschantz, but are you going to follow my example or not, it's entirely up to you (as it's not something obligatory).

So, once again, if you are using the photos under such or similar (not demanding) licenses, you even DON'T have to put the photo source link at all.
But, putting a fake photo source link (which is even a referral link) is a big NO, NO not only on Steemit but in general when we talk about the online publishing.

I hope I manage to clarify to you a few things and what I was really referring to. 🙂