EK046 is the daily A380 service between Frankfurt and Dubai. You will be arriving at Concourse A of Terminal 3. This is the dedicated area for A380 flights.
Your connecting flight EK570 is on a 777. This means you'll have to take the APM (the automatic people mover, ie. train) between Concourse A and Concourse B both of which are still in Terminal 3.
If you are quick, you can make this transfer in 45 minutes - but don't panic as the transit time shown on your ticket will be sufficient to meet your connection (assuming your incoming flight is not delayed unnecessarily).
The fastest transit I have ever booked was for an hour.
If you have less than 1 hour 15 minutes, I would personally caution against doing any shopping as it will easily eat up your time. Also note that the gate will close 20 minutes before the departure time of your flight.
Having personally done this A380 - 777 shift, here are some tips:
It is quite a walk (be prepared by wearing comfortable shoes).
You don't have to deal with much of a crowd, except at the initial security checkpoint. Remove belts (shoes you can leave on) and remove your laptop. Liquids are not allowed beyond this point, unless sealed in a clear bag. You don't have to remove your liquids from your luggage for separate screening (unless advised to do so, which will be after you have passed the metal detector).
The elevators are automatic; and run in pairs of three (three to descend, then the next three will ascend). Take the elevators if there is not a crowd; the escalators and stairs will also get you down, but its quite a trek and takes longer.
There is limited seating on the APM and during summer it will get hot as it passes outside.
Once in the other terminal, you'll have to climb back up to the transit lounge. Again, take the elevator whenever possible.
As soon as you arrive at the transit lounge of Concourse B (you'll know you've arrived as you'll see the latest sports car that they are giving away, and the giant waterfall) check and confirm your gate with the information kiosk or at the automated desk - simply scan your boarding pass. This will tell you how long it takes to walk to your gate and which direction it is.
Now you can relax - there are plenty of quiet rest areas (mainly near the gates which are behind the main corridor where all the duty free shops are).
Free public showers are also available here (just look for the signs) and if you want to eat at a nice restaurant (and not fast food) you'll have to walk to the end of the concourse (past the main shopping areas).