Urmstongran you said that MD made repetitive remarks. Look back over you own posts regarding mine!
No inside knowledge, but somehow I doubt if HM was overjoyed at meeting Trump. It was, as has been pointed out, a photo, easy to capture a fleeting look. Of course she smiled, she is a professional, and polite at all times. She could hardly have greeted him with a scowl, could she?
Urmstongran so you are "of the opinion that HM looked very happy, not just protocol demanded politeness"
You are of course entitled to hold, and express any opinion you choose, as indeed am I.