I think if I saw my doppelganger I'd think, at a minimum "He has a familiar looking face". I'd probably also think, at a minimum, "I've seen that guy around somewhere before."

These faces aren't really that similar. The doppelganger effect is mostly coming from similar clothing, hair style, facial hair, glasses, and so on.

To use an example, look closely at the features one by one of the two men. Individually they're all pretty significantly different. But your eyes gloss over the differences because the hair, glasses, and beard are nearly identical. However those are all changeable features. Grow the hair out, shave the beard, and lose the glasses on one of them and they'd be far less doppelgangery.

I've had this happen to me. It's pretty uncanny actually. I didn't stop to chat with him, but I could absolutely tell by the expression on his face that he was thinking the exact same thing as me.

There's also a local news caster that looks dead on me (albeit, with nicer hair). So much so that multiple people have sent me pictures of the person. It's very weird to see "yourself" on TV.

So, to answer your question: yes.

I think I'd be too distracted by puffy-tailed dogs.

HERE PUFF!

I'm sure it depends on the person. A lot of people spend a lot of time staring at their own faces in the mirror and carefully examining hundreds or thousands of photographs of themselves. Whereas I'm pretty sure that my doppelganger would vaguely remind me of someone, and a day or two later I'd realize the person they reminded me of was me.

Yeah not me… I always wonder what is going on in movies when the character immediately recognizes themselves.

I would for sure. I often come across similar looking persons (height, haircut, style, etc.) and it’s kinda awkward enough, I don’t think I wouldn’t realize I’m in front of my doppelgänger.

Is my Doppelgänger an enantiomorph?

the same way you recognise yourself in a mirror