ぶる details
Examples
put on airs of; act like — affects a trait or status the speaker doubts is genuine, always with a note of mockery
あの先輩、後輩の前でちょっと偉ぶるんだよね。
ano senpai, kouhai no mae de chotto eraburu n da yo ne.
That senior of ours puts on a bit of an air of importance in front of the juniors. casual
彼女は人前では上品ぶっているが、家では全然違う。
kanojo wa hitomae de wa jouhinbutte iru ga, ie de wa zenzen chigau.
She puts on refined airs in front of others, but at home she's completely different. neutral
若い担当者がベテランぶった態度で説明するのは、いささか気になります。
wakai tantousha ga beteranbutta taido de setsumei suru no wa, isasaka ki ni narimasu.
It is somewhat concerning that the young staff member explains things with the attitude of a seasoned veteran. formal
Formation
i-adjective stem／noun＋ぶる（偉ぶる・上品ぶる・学者ぶる）attaches to noun phrase (schematic)
Notes
over status/character nouns (通ぶる, いい子ぶる) and a small set
of i-adjective stems (偉ぶる); never takes a free clause the way
ふりをする does.
Related patterns
Similar
Both derive a verb from a closed set of words describing a person, but がる reports a feeling the speaker takes at face value as genuine (痛がる "acts like it hurts," no doubt implied), while ぶる reports an affected pose the speaker doubts is sincere (偉ぶる "acts self-important") — がる is neutral, ぶる carries a built-in note of mockery.
ふりをする names the pretense's whole content as a free clause and covers any performance at all (寝たふりをする "pretend to be asleep"); ぶる is a bound suffix on a closed set of TRAITS (偉ぶる, 上品ぶる, 学者ぶる) and takes no free clause — ×知らないぶる is not a word, where 知らないふりをする is fine.