When Joe Wolf pulls the tablecloth off to cover the singer, there is clearly a table under it and a vase atop the table, because it's a "pull-the-cloth-off-stuff-stays-put" sight gag. However, in less than three frames, both table and vase have vanished, shortly before appearance of the horse.
When Joe Wolf first enters the saloon, a dog cowboy licks his hand and rolls onto his back, wagging his tail. Joe kicks the dog and he runs off, but his tail apparently has vanished.
However, based on the viewing angle, the dog cowboy's tail might be hidden from view because it is down between his legs - as any chastised dog would do.
However, based on the viewing angle, the dog cowboy's tail might be hidden from view because it is down between his legs - as any chastised dog would do.
When crossing the highway at the 'boulevard stop', the Wolf makes a fatal (for a human; not for a Toon) mistake - he looks left, then right, then crosses without looking left again. Looking left the second time ensures that no traffic is coming in the lane the crosser is about to enter.