Yes, I think you are.
The definition by Evan is a good, descriptive one. The example that follows ... sitting on one side of his butt ... is only ONE of the possible manifestations.
Bugging is not so much a specific behavior, but rather a mindset the dog has ... he wants to avoid whatever he thinks is coming next. You try to "read" that mindset through his behavior. But you need to observe the entire behavior in the situation, to decide if your dog is bugging. Sitting sloppily could be a form of avoidance (bugging) or it may be just a sloppy habit or bad hips or fatigue or whatever. What is the dog's entire demeanor? Is this demeanor only present when he is faced with what he perceives as "scary" predicaments? If he demonstrates this same demeanor in normal, happy situations ... for example, if he sits sideways while you are fixing his food bowl ... it's probably not bugging.
In the pictures, what I see first is his disinterested, non-attentive gaze off to the side, looking away from you. While he was doing this, were you trying to get him to look at you? It does not appear his attention is focused on a distraction ... ears not up, etc ... so if you were trying to get his attention and he was looking away, pretending to be bored, hoping you would quit and leave him alone, he may have been bugging. You have to look at the whole picture.
Now if it IS, how will you deal with it?
JS