KanjiJLPT N1
Net

gauze, thin silk, Rome, arrange, spread out

Mnemonic

Your eye locks onto a rare bird perched high above. To sustain your family, you must catch it. You cast a wide, gossamer net between the branches—nearly invisible. Holding still, your eye follows every flutter while you sustain the net's spread, until the bird drifts in.
Additional thoughts
Imagine a hunter's keen eye guiding the placement of a nearly invisible gauze net between jungle branches. Sustain conveys both the need to feed the family and the act of holding the net taut. Eye watches, sustain keeps it spread—together they form the Net.
Quick recall
Your eye tracks the bird as you sustain a gossamer net spread wide between the branches.

Details

The keyword for 羅 is net. This kanji refers to a net used for catching birds or other creatures, evoking the image of a fine, gauze-like mesh spread wide to ensnare. By extension, it carries the meaning of spreading out, arranging, or enumerating things in an encompassing manner, as in gathering and laying everything out systematically. It also appears in phonetic borrowings from Sanskrit, most notably in words related to Buddhism.
On'yomi
Kun'yomi
うすもの