It's Mike spoiling Christmas for one of his parents and thinking he got away with it.
Panel 1: We see him at the crawl space where he would one day find the Miracle Dress; right now, he's found something else and thought-bubbles "No way!! I bet this is the monster truck I asked for!!"
Panel 2: As he starts to unwrap it, he thinls to himself "Maybe if I pull the tape off ve-e-e-e-ry carefully...."
Panel 3: He's horrified to find that it's 'just' a stoopid coffee maker; it'll be until he has children of his own and a computer to ticka-tacka-tappa away at for him to appreciate this present.
Panel 4: With his face scrunched up, he hastily rewraps the gift in a flurry of sound-effects and thinks "There!..."
Panel 5: "...They'll never know I touched it!!" Given the horrible job he did, something tells me they will.
Summary: It seems to me that Elly might actually have been smart enough to hide his and Lizzie's presents where he'd have genuine difficulty getting them; this leaves me answered with a question mark. That's because I don't know if he'll be yelled at for opening things or be made to endure someone crowing about outsmarting her child.