Hey guys, I've got a quick question about the usefulness of Minor Illusion, and I wanted to know your thoughts.

Recently our party's Arcane Trickster has started to use Minor Illusion to create still images or facades in order to hide himself and others during combat & situations where they are required to use stealth.

For example, in our last session he hid in a small alcove and used minor illusion to create a 2-dimensional 'image' of the alcove to give the impression that it was empty, then stepped out and used his sneak attack bonus to kill a passing monster.

This is not the first time he's done this '2-dimensional image' thing - on multiple occasions he's used it to hide other party members in a similar fasion, and escape from bandits by creating a fake image of himself and the surrounding room between him and the bandits (allowing him to escape out a nearby window).

Is he overstepping the power of the spell at all? I feel like he might be, but I'm not sure if that's just me being pedantic. Should I pull him up on this kind of thing from now on, or just let him go with it?