Some strange behaviour

Just after some advice really.

A couple of months ago I was playing with me RBI mare & I asked her to touch her cover which was laying on the ground.

She happily walked up to it & then lowered her head stuffed her mouth as full of canvas as seh could get it then stood there, not making any movements except to blink.

She wasnt sucking the cover or anything like that.
It was just really strange.
I just stood there & hung out with her for a few minutes until she decided she would wake up.

She approached calmly & she woke up calmly.

It kind of reminded me a bit of Allure when he goes catatonic with the cookies but she was just still and her eyes although a bit dopey looking were stil lblinking.
but she was standing with her head lowered & her mouth full.

Anyone else experienced this?