Continuity mistake: When Violet and Klaus are rubbing the floor, as the door opens, you can see them both lift their heads to look. When it cuts they lift their heads again. (00:14:20)
Continuity mistake: When Violet opens the closet and finds the rat inside you can see a cup beside the rat to the left. When it cuts from a view inside the closet you can see it is a different cup and its handle has changed position. (00:14:20)
Continuity mistake: When Olaf arrives with his acting troupe while Violet and Klaus are scrubbing the floor, a small stool can be seen a few feet behind Violet. A couple of shots later the stool has moved right behind her. (00:14:30)
Continuity mistake: When Count Olaf enters with his acting troupe, Klaus and Violet are rubbing the floor and Olaf says "Imagine my surprise." Violet places her left hand on her lap. When it cuts she place her hand on her lap again. (00:14:35)
Continuity mistake: As Count Olaf with his acting troupe enters the house and one of them says "Ugly little people," there's a red can and a yellow box beside Violet and Klaus. Two shots later, the two items have suddenly moved closer to them. (00:14:45)
Continuity mistake: When Olaf and his acting troupe are gathered and he sits down and says "Now who shall play the most handsome count in the world?", he has his hands folded resting them on his left armrest. When it cuts both hands rests on each armrest. (00:15:45)
Continuity mistake: Right after Olaf has asked who should play the most handsome count it cuts and we see the acting troupe from behind. We can see Luis Guzmán's character holding his glass still by his chest. When it cuts he is suddenly drinking from the glass. Also the people on the couch change positions between the shots. (00:15:50)
Continuity mistake: In the beginning, when the camera zooms out of the picture of the burned house, we can see Lemony holding the picture with both hands. When it cuts he's holding it with one hand. (00:16:15)
Continuity mistake: When the orphans are making pasta for Olaf, Klaus takes off a window screen and calls it a strainer. As the camera changes shots the arrangement of water droplets change on the screen. (00:16:35)
Continuity mistake: When Violet pours the spaghetti out of the spittoon over the strainer, all of it goes out of the spittoon and nothing is left. When it cuts, a spaghetti strand hangs over the spittoon's edge. (00:16:55)
Continuity mistake: When Violet and Klaus are setting the table, Violet puts her first plate on the table. When it cuts she puts it on the table again. (00:17:15)
Continuity mistake: When Violet and Klaus are setting the table for dinner we can see a chair right next to the edge of the table (on the opposite side of the rehearsing room). But when Violet and Klaus are done setting the table and Violet places the cup of cutlery on the table, the chair has been moved and can't be seen. When it cuts the chair is back. (00:17:20)
Continuity mistake: When Violet is done setting the table she sits beside the table and starts brushing her skirt with her hands. When the shot changes she suddenly has her hands together. (00:17:25)
Continuity mistake: When the Baudelaire children set the table for Count Olaf and his acting troupe you can see and hear them set seven places, but when you are shown the aerial view of the table there are only six place settings. (00:18:00)
Continuity mistake: When the Baudelaire tell Olaf that dinner is served you see two plates on the left side but then the camera angle changes to the Baudelaire's view and now there are three plates. (00:18:10)
Continuity mistake: Right before Sunny bites Count Olaf after the Baudelaires have made dinner there is a shot where Klaus says "No" to Olaf. When it cuts, Olaf's hand has suddenly appeared out of nowhere beside Klaus' head. (00:18:40)
Continuity mistake: When Klaus moves the planks from the window in Olaf's house he gets white spots of dirt on his shirt. When it cuts to him saying, "How could they do this to us" the spots are gone. (00:20:05)
Continuity mistake: When Violet is telling about that time when their parents had written a long letter that got lost in the mail, her ponytail hangs behind her right ear. When it cuts, it's over her ear. (00:20:50)
Revealing mistake: When Violet and Klaus make the tent inside their bedroom in Count Olaf's house, they set up the light with the faces of their parents on it in front of it. Except when it shows the shadow of the object outside the tent, the edge of the picture frame isn't showing when it should. (00:21:40)
Continuity mistake: When Count Olaf and the Baudelaires are driving home from court, Olaf says "Children, I've been contemplating our situation." while looking at the kids in the mirror. It cuts as he says "situation" but now he is suddenly looking straight forward at the road. (00:22:10)
Chosen answer: The spy glasses are not explained in the books, but it seems that these are symbols of the fact that they are in VFD, the secret organization we learn about later on in the series. Both Dr. Montgomery and Aunt Josephine's husband and brother-in-law, the Anwhistle brothers, are implied to have been a part of VFD.