It makes sense. The space of moves is a tree. If you're doing a breadth-first search and a grandmaster is doing a more depth-oriented search with heuristics for pruning low value branches, then the same total number of moves could be considered, but the grandmaster is reaching the better moves before you.
It's not a tree since you have transpositions. It's a directed graph, since it has cycles.
No, a grandmaster can also consider moves way faster than an amateur. Watch Hikaru Nakamura solve chess puzzles [1]. He has already solved the puzzle and moved on to the next one before an amateur can even see the pieces on the board.
[1] https://youtu.be/4EfSymvT59M