Tā zhè shǒu shī zhǐshì yìngjǐng zhī zuò, méi xià shénme gōngfu.
This poem of his is just a token piece for the occasion — he didn't put real effort into it.
Tips
usage
Two flavours: positive ('seasonally appropriate', e.g. red clothes at New Year are 很应景) and slightly dismissive ('done just to suit the moment', as in 应景之作 — a perfunctory occasional piece). 应 is read yìng (4th tone, 'to respond to'), not yīng.