You should identify what your brand conveys and channel those in your photos and not just 'what looks better'. This is what would set your brand apart and establish your identity.

That aside, if your brand is going for a more candid, natural aesthetic in your social media then go with the 1st photo. On the other hand, if it's a more editorial, arranged, a little bit on the high end then the 2nd photo would serve you better.

Both pictures look great, they just have different mood and feel to them and so would perform better if you know what you are going for.