You can't really tell because the two of them wouldn't sit for a picture, but that other dog is a big brindle boxer. His name is Carter. His person's ex-husband used to be best buds with my ex-common-law, so Tinky-Winky and Carter got to know each other. Then Carter's person and I got together to commiserate about our exes, and we got to be friends, and we walked the dogs together, and on occasion I've taken Carter along on our walks. He's a nice dog when he gets to know you.
So, Tinky-Winky and Carter are friends. As you can see in this photo, that means mostly that they don't fight. Mostly they ignore each other and pay attention to the humans around them. Some times Carter will play-bow. Tinky-Winky has no concept of how to play with another dog, but she's at least not afraid of Carter when he play-bows. If he gets into her personal space she'll bite his nose, but he's wise to that and gives her respect.
That's how a good pack works. Everybody calm and quiet and in their proper place.