God can use any job or any task in our lives to glorify Himself. We can do all things for Him. That is where the meaning comes -- doing it for Him.
Paul writes in 1 Corinthians 10:31, "Whether, then, you eat or drink or whatever you do, do all to the glory of God."
On the reverse side is if you have a really important job to do -- if you don't do it for God, it will just burn up in the fire. it will prove to be without meaning for you eventually. But if you can look back on it realizing God was with you every step of the way, you will say, Thank you Lord for that opportunity.
This thought has come to mind because it applies to something I'm doing. I really have no idea how God is going to use it but I feel the necessity to do a certain task. My human side tells me it all might be a waste, but then I remind myself that nothing is wasted if done for God. So as I embark on this task I'm doing it for Him.
Think about the Bible. The Bible writers had no idea their writings would go all over the world and be read continuously for thousands of years. They just wrote because God led them to write down what He told them.
A small thing -- someone planted dozens and dozens of lilac bushes on the place we live. That person had no idea those lilacs would be enjoyed and God would be praised for them by a woman named Jane years later. Those lilacs, when in bloom, bring me such joy. And even if the person somehow knew this and didn't really care about me enjoying the lilacs, God cares and He finds great joy in my enjoyment.
We don't know how our work for God will be used in other people's lives. Most of the time we will never know. That's okay. We can do it for God and let God use it any way He wants to.