He was chief architect for the Nordwestdeutsche Gewerbe- und Industrieausstellung (Northwest German Trade and Industry Exhibition) of 1890; the Festival Hall for this was later known as the Park House.
From 1881 to 1907,[6] Poppe was chief interior designer for the ocean liners of Norddeutscher Lloyd, the first "lay" (non-marine) architect responsible for entire ships,[7] and transformed them into floating hotels.
[11][12] When Albert Ballin commissioned the first express liner for the rival Hamburg America Line, the Augusta Victoria, he hired Poppe to design the interior.
His ship interiors have been described as "overblown, over-decorated, and dark",[16] as "a seagoing baroque collage of high ceilings, massive pillars, gilded balustrades, trumpeting cherubs, and gigantic statuary,"[10] as "temples of high baroque, grand galleries of an aspiration so Valkeyrian that only megalomaniacs might dally there in comfort or good conscience",[17] by Cunard executives who visited the SS Kaiser Wilhelm der Grosse and SS Kronprinz Wilhelm in 1903 as "bizarre, extravagant and crude, loud in colour and restless in form, obviously costly, and showy to the most extreme degree"[18] and by a contemporary American as "'two of everything but the kitchen range', then gilded.
"[10][19] The architecture critic Walter Müller-Wulckow described the Bremen Cotton Exchange, which started to shed its profuse ornamentation after exposure to the elements, as the "crassest" manifestation of "cancerous" building styles.