It might not work since they’re different platforms with different APIs. The only way an app might work on both platforms is if the app itself chooses to support both APIs.
That said, there’s a level of interaction between the two since they both use ActivityPub. I.e. on Mastodon I can search for a particular Lemmy user and see their posts.
Pick up a light dumbbell and see how long you can hold it. Take a rest and pick a heavier dumbbell and see if you can hold it for as long as you could with the lighter dumbbell.
You can also try and see how far you can walk while holding either the lighter or the heavier dumbbell.