Apple Watch "Mark as Missing"

[AmesLog198]

Good afternoon Group. Quick question about the activation lock/Mark as Missing for ios2 watch. Long story short. I left my Watch at work on the Charger within range of WIFI, my pass-lock disabled. (did that few days ago since I was playing around with it and forgot to reactivate I think) So the watch is on, its charging, pass-lock disabled. If I place it "Mark as Missing" does this lock the watch down completely? I'm not so much worried someone is going to physically take the watch more I'd just like to know if someone is still able to open and read all My Messages, Emails, ETC? Activation lock instruction seem to only say it disables Apple Pay, and makes it impossible for someone to re-pair it to another device without my AppleID. Sorry if the question seems dumb just can't seem to find a simple answer if it actually locks the watch completely. I've never used the Mark as missing feature before. Thanks group.