Grant featured a cartoon-like style in his work that was lively and attractive. It was also highly in tune with the times. Yes, there was a Depression and then a war going on during his peak years. But many Americans were happy to seek relief from unpleasant times by viewing escapist movies and gentle cartoon humor, so Grant did well in difficult times.
As for me, I have no problem with his artistic style, given his objectives and assignments. My problem is, ... well, let's take a look.
Grant had a sense of humor that must have appealed to some magazine editors and readers, but it largely eludes me. For most of the images in this post including this one, I can think of possible situational jokes; however, none is smashingly obvious.
Snap, Crackle and Pop grew out of Grant's frequent usage of gnomes in his other illustration work, as in the Judge cover above.
The cowgirl is carrying a tennis racket and shoes. I have no definite notion what that signifies here.
Okay, I think I get the humor here. It contrasts traditional, dress-up type dancing with the Jitterbug dancing whose popularity was peaking around the time Grant painted this cover. His twist, of course, is cross-pairing the dancing couples -- perhaps parents and teen-age children.
The illustration was surely completed before the Japanese attack on Pearl Harbor, 7 December 1941. It shows a sailor returning from duty in a warm climate. Not exactly war-related, but Collier's editors must have decided that the cover wasn't worth pulling at the last minute, production times being what they were.
Another sailor, another somewhat opaque joke. For once, it's the girl who has to wait for the date. But why is the sailor sleeping? It would be better if Grant provided a reason.
Grant often used sailors in his wartime illustrations. Here he deigns to feature a couple of Army corporals. But the humor? Are they writing each other? Someone else? Who besides Grant and his editor knows.
I have no clear idea who the head in the crystal ball might be.