I guess it depends on how you say it

I've never interpreted someone complimenting a tattoo as flirting, and it's actually never even occurred to me that it could be. But I also just assume anyone who isn't being creepy isn't flirting with me because in my mind "flirting = creepiness" for some reason, so.

I once said “cute dog” to a man as I petted his dog and he looked at me like I’d said “I want to have your babies”, so, yes, yes it could.

Maybe, some tattoos look sexy on the right canvas... oops was that flirting?

Nah, I didn't read about this in "Fundamentals of Flirting".
But Seriously it might be interpreted as flirting depending on the situation and how you tell them.

Could be.

It can be. I do it a lot when I'm flirting because it's like a guaranteed way to flatter someone.

It depends if as a woman u compliment a guy on his ink he will think you're flirting with him cause we all think women are flirting with us. :p i always compliment ppl on their tattoos, admittedly i do compliment women more. cause i think girls with tattoos are hot:)

Any sort of positive, or even negative response to another person can be a flirt. A simple and innocent compliment can be understood as more.

It can be - flirting is a state of mind, a vibe, not necessarily precisely what's being said, you can be flirty about anything

It could be, but I get normal no-strings-attached compliments on my tattoos from cashiers and passersby and people at the gym all the time. Well, I'm assuming it's just a normal compliment. When people flirt they usually try to carry the conversion beyond just the tattoo. There has to be more than just a compliment to signify that it's flirting tbh