At some point in my market run, I'll come across this situation:
I want something on the shelf, but someone else is in the way.
They aren't moving, they are moseying about and wasting time, perhaps even texting, but all DIRECTLY IN FRONT OF THE THING I WANT TO BUY.
So, I'll stand there awkwardly, panic rising, as I just wait.
If I am particularly unlucky, the person in the way will turn to me and ask if I wanted something from the shelf they were blocking.
There is no worse feeling than having a panic attack in public, and having to pretend everything is okay, because you know people won't understand.
Although I can appreciate someone trying to help (especially a complete stranger),
they usually don't know what to do, or what they try just makes me panic more.