http://www.itv.com/news/2018-08-10/campaigners-slam-disturbing-pony-painting-parties/

What do you guys think?

 not much to think about. people are idiots 

it washes off.

some kids that attend parties have never even seen a horse before 

in those images with the article every horse looks to be in heaven gettin loved on

We have kids draw/paint on ponies every year for kids camp. The horses love the attention and it’s a fantastic way to teach horse anatomy hands-on :)

i mean, people are weird and it's kinda garish looking but as long as it's non toxic and the ponies don't actually mind i don't see the issue? i guess in the right circumstances it could even be helpful if it means they're are used to being touched/groomed all over, and i bet the kids enjoy it. not sure why they made the jump to chalk instead of just teaching the kids to groom the ponies but that's neither here nor there.

besides if the pony wasn't enjoying it i'm pretty sure they would've found out real quick.

Honestly, there are way worse things I can say about PETA in this article, but that would break HP's guidelines so I will say this the most polite way I can; although typically I ignore their usual kinda gimmicks like this, this is something that really annoys me, not only for the fact that they are lying to fit their own bias, but because they simply do not understand the whole concept so they want to ban it and it's annoying. Secondly, how can you say, "children would not like to be forced to stand still while someone painted and drew all over their bodies, so why do it to a horse?" to kids? Like, have you met them? Do you know what little kids - who usually do this - are like? They do this to themselves frequently with no signs of being upset about it!

I'm not going to say that horses particularly love it - only because that's not always the case for some horses - but they certainly do not hate it, do not feel traumatized, or any other exaggerated word you want to put here; the only thing that would truly concern me is the paint itself being toxic, but this is chalk paint, which I have used many times on livestock. It does not hurt them, it does not irritate their skin and, depending what kind you get, usually washes right off them.

I see this beneficial to horses too, especially if they're rescue horses like some I knew used to be, and every horse in the images shown look pretty relaxed or just nonchalant about it, so I really don't get the fuss here.

I think painting horses is pretty harmless as long as it’s non-toxic paint and it’s washed off after. As far as mistreatment of horses goes I think there are much bigger fish to fry.

Pretty much agree to what's been mentioned above.
We "decorate" our ponies for camps and our riders' horse show at the end of each session.
Our guys don't mind and our riders love the hands on art, sometimes hand print art on the ponies themselves.
We use non-toxic and wash away once riders are gone. :)