A young artist agreed to undergo a series of stomach-churning "animal tests" in a London store window to promote the use of cruelty-free cosmetics.

Onlookers watched with both disgust and bewilderment on Tuesday as the woman was restrained, force-fed and slathered with lotions in a Lush cosmetics store on Regent Street in the city's west end.

Dress in a nude-coloured bodysuit, performance artist Jacqueline Traides agreed to be prodded and manipulated in public to raise awareness for the company's "Fighting Animal Testing" campaign.

The abuses began when a fellow performer in a white lab coat and surgical mask yanked Traides' head back and stretched her mouth open by fixing two hooks to the corners of her mouth. The hooks were held in place by a strap behind her head.

From there, the apparent experimenter spooned an orange-yellow mush into her open mouth. She made choking and gagging motions as the food was dribbled onto her tongue.

At that point, a crowd of pedestrians and reporters began to form outside.

The person in the lab coat then pulled a medical curtain around the girl, making her visible only through the store window. The curtain implied privacy, but there was none to be had in the demonstration.

After that, Traides is experimented on with lotions and oils. She writhed in apparent discomfort as an irritant was sprayed in her eyes.

The person in the lab coat then fixed a tangle of red wires to Traides' head by wrapping black bands around her head and wrists. Upon being connected to the device, she shook as if receiving an electrical shock.

Though it's unclear whether the entire demonstration was simulated, Lush representatives have said that Traides was safe and supported throughout the show.

While Lush's campaign is intended to shine a light on the plight of animals used for cosmetics testing, Tuesday's grimace-inducing show is reminiscent of tactics used by other animal rights organizations.

For instance, People for the Ethical Treatment of Animals has drawn criticism over the years for its use of barely-clothed female models in advertisements. Detractors have accused PETA of furthering its cause with sexist campaigns and shock tactics.

For its part, Lush maintains that staff tried to ensure the comfort of its performers and the public during Tuesday's demonstration.

In a blog entry, the company said "staff stood outside the shop and ensured that children and their families were warned against the spectacle whilst still being encouraged to sign the Cosmetics Directive 2013 petition."