Can You Make Commercial Tenant Change The Sign?

[Chris G.]

Manage a 4 unit commercial plaza, one tenant is franchise and the sign is very professional, the other tenant has a large window decal that looks professional too, the other tenant however has tinted out the windows so dark you can't see inside and used these window markers to write their social medias on there which looks awful tbh they do have a small window decal on the door but you can barely see it from a distance. I don't find the shop to look very welcoming with the tint or smeared markers for the social medias which I feel also makes the plaza look bad. In the lease it pretty much just states they need to keep up with maintenance and follow the laws for signs/ advertising. It also states they need to get permission but because they we're a tenant before I managed that's why they didn't have to ask me. Would I be over stepping to have them only use real signs/ decals and no tint rather then markers or is it typically the tenants right to choose how they advertise their business?