I'm a steward at Sheffield Arena...
When the floor is set out in blocks, as shown, it is almost definitely going to be seated. On standing floor events, there is usually no blocking and simply a large 'standing' floor block covering the whole diagram.
B13 should give you a decent view of everything, I would imagine.
I would imagine that the 'B stage' would be used for certain parts of the concert, however with a main stage being shown on the diagram the majority of the concert should be there.
If you have any concerns about seating, you can go to information on the concourse roughly behind where block 109 is. Sometimes if there's a big issue where you are sat, we can re-locate you if there's a spot.
Usually with seated floors, we as stewards are required to 'make' people sit down by practice, however on the night everyone might tend to just stand up with the kind of concert it is, which as you can imagine it's hard to make an entire floor sit down.
Like I said, I would imagine it's a seated floor with the way that it's shown out, however, we've not got any information on the concert yet. Feel free to PM me if you've got some queries, as I am most likely to be working there that night.
And last, the tickets don't usually have pictures printed on them. Usually we just scan the tickets and our scanners will blink green if you've got a valid ticket.