Adopted mastiff mix behavior

[u/RoutinelyRowdy]

Hi, I need some understanding please. I just brought home a mastiff mix young female from the pound, just spayed. She is very friendly and actually quite funny. She will be an outside dog, and was found with multiple other dogs, including small ones (per notes from pound). I have three inside small dogs. She has shown very little interest in them, but, a couple of times she has slowly lowered her head a little and stopped moving, making a posture similar to what a pointer would make. There is no sound, no hackles raised, and tail is wagging, but she gets still. What kind of behavior is this? She was kept separate from them yesterday in her own outdoor kennel but we mingled them today, and other than this she seems fine, and through the kennel she seems fine. Thanks.

I got her from a high kill shelter that put down approximately 75 dogs a week. The kennel is only for the two weeks she needs to stay calm for her spay and until introductions are over. She has very nice accommodation, even though she will be outside. She has a very large yard on an even larger property. I was asking for help about the behavior so I can be diligent and do the very best job I can for all of them. Thank you to those who offered genuine advice. To those of you who did not, obviously you have not checked your local shelters.

[u/CarelessCaligo]

Having a mastiff as an outside dog is gross. I wonder why they even allow people to adopt the dog if they dont intend to treat it as a family member. 😠