Well, I'll give you my personal perspective as a coworker and a manager - I worked in a very busy retail environment for 8 years, with 3 of those as management. My perspective is not going to be everybody's perspective, and will obviously be coloured by my specific stores (high volume, stressful, medium-large staff).

Retail can be tough, and everybody has exceptionally bad customers sometimes. Crying is not unusual, but it's not something I would expect to happen regularly. There's an element of needing to be able to brush things off when you deal with the public.

So as a coworker, if I was scheduled often with someone who regularly needed to go off the floor to get themselves together for as long as 10 minutes, it would get annoying quickly, because other people have to pick up that slack. Everyone has moments that they break down, but it's more like a once in a while thing and not a regular occurrence.

As a manager, if you regularly seemed like you emotionally couldn't handle the job, I'd start reassessing whether you were suited to that specific position or not, especially if you were a cashier. I might consider transferring you to stock or regular floor duty, because to be honest it would not be acceptable to me for a cashier to be going off the floor to compose themselves for ten minutes at a time on a regular basis. That would be doubled for holiday periods, where it's going to be even more busy with customers who have even less patience (and therefore kindness) than usual.

There'd be a grace period, obviously, as a new person adjusts to the job requirements and stress levels, but after 6 months if it was regularly happening I would start reevaluating your fit in your current position. If you were a cashier, at 6 months you would have already been transferred to another position.

For context, I'd consider "regularly happening" to be once every week, with "occasionally happening" as every 6 weeks or so.