From the original artist's point of view: You just tagged someone on *my* post telling them to copy *my* artwork. Don't do that. Seriously! I don't care if they *can* do it better or whatever reason you might possibly conceive for being okay with this. It's the equivalent of someone walking into your job, standing right in front of you, and talking with their friend about how they should totally apply to take your position. Umm...hello? This is our livelihood people! Don't encourage people to steal our ideas! Trust me...they *really* don't need any encouragement.
From the artist you tagged point of view: Why are you suggesting this to me? I don't make this type of art and even if I did, I don't want to steal someone else's design/idea. But I'm going to be polite, smile, maybe even come up with a funny way of gently declining. I might even feign interest and then never produce anything like it because it's not my thing. Instead of inspiring me, you've created an awkward situation between the original artist and myself where if I chat them up, their going to be suspicious as to my intentions and worry I'm going to steal their designs. Plus, there's that whole "individuality" and "originality" thing us artists have going on that will most likely make us *not* want to make whatever it is you suggested just out of spite...and because we want to do our *own* thing. I mean, yeah, I can look at some art and be inspired to use the technique or even make something similar but if it's "suggested" that I do...yes, I'll cut my nose off to spite my own face.
What to do instead: Tag an artist in a comment *without* suggesting they make something similar. That easy. If the artist is inspired by it, GREAT! If not, so be it.