Confidence: I'm as sure as I can be.
Notes: E. monodactyla sits with its left and right wings in a perfect straight line, and with less lamina showing. G. pallidactyla is statistically more likely, being a common moth with a widespread foodplant yarrow (and sneezewort?) whilst G. ochrodactyla feeds on tansy and seems a lot less common. I'd be ill advised to say which species your photo represents. Both these species were in the genus Platyptilia until very recently.