I don't have a photo on my SA profile.  It's not a deal breaker but no doubt, it narrows my field.  Following the initial message exchange, I'll move to a differ platform and share a photo.  And like many, I have sent out a few photos only to be ghosted.  But that's life.
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Recently, as a pure fluke, I sent a photo to a POT SB that was of me and one of my past sugar girlfriends - outdoor photo with both of us standing side by side.  The recipient immediately complimented me ... she's so cute / you two look good together / etc.  From there, that is all I do - send out a photo of me with one of my SB's (current or past).  Most recipients have replied with a positive comment.  While I can't quantify it, I sense it has worked to my clear advantage.
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Possibly, a POT SB is more comfortable with a POT SD knowing that he has dated other good looking women?

A lot of unknowns here.. it seems you want to protect your privacy, but there are ways to do that with blurring or cropping.

From what I know the SBs are not necessarily looking to see how handsome you are but many want to see a pic to know you're a real guy, not overweight or hideous. Some won't respond if you don't have a picture, so you would need something else compelling to attract their attention.

As to pics with another SB.. it's not something I would do but if that works for you... some gals might get off on the idea that you're a playboy and won't get too attached, but others may be looking for a different kind of relationship.  Also.. it may be a bit uncool to share a picture of a lady without her permission, though it's unlikely to come back to bite you.

Being seen with hot looking chicks is a form of social proof.  Other chicks regard that as proof that you hcan attract other hot chicks, and thereby are enhanced in their own eyes.

I agree with Scaramouche; don't post pictures of past SBs, or anyone for that matter, without their consent.  Back in 2017 I dated a lovely college girl for a short while.  A few years later I dated a different girl who I had a serious year long arrangement with.  Looking at one of their Facebook profiles I was astonished to see they were in the same sorority in college and knew each other!  But neither of them know the other was sugar dating on SA, and it would have been seriously indiscreet to out either of them.  Good idea not to post recognizeable photos of anyone but yourself.