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What image did you use? Can you link it?

I usually go for a stock photo but seems referencing to that isn't enough unless it has a Creative Commons 0 license. I do link it as image source. That's okay right?

If you're not sure if the photograph is licensed under the CC0 license, then it's better to either find that out before using it and contact the author, or simply do not use it. Naming/crediting the author is mandatory, even after purchasing a license for use.

Better to use my own photos, all in all. Thanks for the explanation @rubencress.