How do your help your doggies get over everyday household items?

My pup flips put at the new swivel chair I got for my desk (barks like mad when no one is sitting in it, that's always fun in the middle of the night). We've brought her over to sniff if, I've fed her treats while sitting on it. I've held her and sat on the chair. At those moments she seems ok.

She also goes a little looney at her reflection in the mirrior. I have a weird set up in the apt and I have 2 mirrors built into the wall and one is low. Since I work from home I've had to resort to covering it with a towel.

If anyone has ideas it would GREATLY be appreciated