The photo I uploaded online for DS160 is a little older than 6 months but shows no physical change to how I am now. But just in case, is it fine if I bring a more recent photo of me for the appointment rather than the same one I uploaded?
Yes, you can. They will likely decide the photo on the application is fine, but if not they will use the new photo you bring.
Using a different photo is common - in fact if you arrive for your interview and they decided the photo uploaded is not good enough (poor quality, doesn't meet the requirements, etc) then they will send you to get a new one taken before you can proceed for your interview.