There are some who think the feeding of the 4000 is just a rehash of the feeding of the 5000. This a notion that has little to commend it. For one, the two incidents are placed quite close to each other and there is no reason why the gospel writers should report the same event twice. Moreover, Jesus Himself refers to two separate miracles.
Once again Jesus is surrounded by crowds, and this time they have been with Him for three days. Now it is Jesus who presents His disciples with the question about what to do for the people. Maybe He is seeing if they have learnt anything from the previous miracle. When God does something in our lives we should not merely accept it and move on, instead we should learn from it so that we react differently the next time.
The disciples had not learnt anything. Jesus asks how many loaves they have. This time they have seven, so they are better resourced than last time!
Once again He gets the people organised and another miraculous food distribution occurs.
The Pharisees came and asked for a sign. This really makes you wonder. What more do they need to see!? Jesus gave them short shift.