Thank you SO much for your comment @shinyforest! :D <3 (Love your name btw..!)
Thank you for taking the time to share your experiences and thoughts on this topic close to my heart. To answer your question, I think in it's essence what makes something look like it's been drawn/painted from a photo is if it looks ''static'' or ''lifeless''. I think the main cause for this impression is when the artist only focuses on copying what they see rather than understanding what they see. Understanding what happens to your subject in a photo requires studying nature, light, form, values and color. It is ofcourse also really important to work from GOOD photos where you DO understand the light situation for example. Some photos have a very flat light and if so, trying to create form and light where there really isn't much to begin with is very hard., especially if you don't really know how those components work.
I hope you got something from my answer and I'd be happy to answer any other question you have ;)
Thank you again Klaudia! <3
I appreciate your support!

Best,
Marie