By doing that, they covered up the names of all the flavours (there are about 20 or so different kinds). So I couldn't see to order (was going for non-standard flavours which change week to week).
I didn't feel comfortable saying anything to the kids because, well, that's the parent's job.
Well, it's the parent's job to say, "We don't block the way," etc.
But you can certainly speak to the children to say, "Could I ask you to let me see the signs? I have to pick my flavor."
Children are people--speak to them exactly the way you'd speak to a grownup: "Excuse me, I need to see the sign that's behind you."
"I'm so sorry, could I ask you to step aside so I can see the sign for a moment?"
Too many people think that the only way to speak to children is to boss them around or scold them or "instruct" them.
Not true. Just ask them for a favor/assistance/etc. exactly the way you'd ask a grownup. Same tone of voice, even--not sickly sweet or stern.