Future Intern at BB — Accessories

So I am fully aware interns should dress as conservatively as possible. However, I am in the process of building out my tie collection and I want to ensure I straddle the line properly.

My ties are currently Brooks Brothers, Zegna, Thomas Pink as well as entirely striped, conservative colors.

What is the threshold for too casual? I really like the Thomas Pink "Elephant And Castle Print Tie" but think it may be too casual for an intern.

Also was thinking about picking up Garmin's Fenix Chronos watch (metal). I'm fairly active and would be using it outside of work, but obviously wear it during the day. What is the prevailing opinion about these kind of watches in the work place?